--- _id: '11074' article_processing_charge: No article_type: original author: - first_name: Emily M. full_name: Hatch, Emily M. last_name: Hatch - first_name: Martin W full_name: HETZER, Martin W id: 86c0d31b-b4eb-11ec-ac5a-eae7b2e135ed last_name: HETZER orcid: 0000-0002-2111-992X citation: ama: Hatch EM, Hetzer M. Chromothripsis. Current Biology. 2015;25(10):PR397-R399. doi:10.1016/j.cub.2015.02.033 apa: Hatch, E. M., & Hetzer, M. (2015). Chromothripsis. Current Biology. Elsevier. https://doi.org/10.1016/j.cub.2015.02.033 chicago: Hatch, Emily M., and Martin Hetzer. “Chromothripsis.” Current Biology. Elsevier, 2015. https://doi.org/10.1016/j.cub.2015.02.033. ieee: E. M. Hatch and M. Hetzer, “Chromothripsis,” Current Biology, vol. 25, no. 10. Elsevier, pp. PR397-R399, 2015. ista: Hatch EM, Hetzer M. 2015. Chromothripsis. Current Biology. 25(10), PR397-R399. mla: Hatch, Emily M., and Martin Hetzer. “Chromothripsis.” Current Biology, vol. 25, no. 10, Elsevier, 2015, pp. PR397-R399, doi:10.1016/j.cub.2015.02.033. short: E.M. Hatch, M. Hetzer, Current Biology 25 (2015) PR397-R399. date_created: 2022-04-07T07:49:00Z date_published: 2015-05-18T00:00:00Z date_updated: 2022-07-18T08:34:34Z day: '18' doi: 10.1016/j.cub.2015.02.033 extern: '1' external_id: pmid: - '25989073' intvolume: ' 25' issue: '10' keyword: - General Agricultural and Biological Sciences - General Biochemistry - Genetics and Molecular Biology language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1016/j.cub.2015.02.033 month: '05' oa: 1 oa_version: Published Version page: PR397-R399 pmid: 1 publication: Current Biology publication_identifier: issn: - 0960-9822 publication_status: published publisher: Elsevier quality_controlled: '1' scopus_import: '1' status: public title: Chromothripsis type: journal_article user_id: 72615eeb-f1f3-11ec-aa25-d4573ddc34fd volume: 25 year: '2015' ... --- _id: '11519' abstract: - lang: eng text: 'Faint Lyα emitters become increasingly rarer toward the reionization epoch (z ∼ 6–7). However, observations from a very large (∼5 deg2) Lyα narrow-band survey at z = 6.6 show that this is not the case for the most luminous emitters, capable of ionizing their own local bubbles. Here we present follow-up observations of the two most luminous Lyα candidates in the COSMOS field: “MASOSA” and “CR7.” We used X-SHOOTER, SINFONI, and FORS2 on the Very Large Telescope, and DEIMOS on Keck, to confirm both candidates beyond any doubt. We find redshifts of z = 6.541 and z = 6.604 for “MASOSA” and “CR7,” respectively. MASOSA has a strong detection in Lyα with a line width of 386 ± 30 km s−1 (FWHM) and with very high EW0 (>200 Å), but undetected in the continuum, implying very low stellar mass and a likely young, metal-poor stellar population. “CR7,” with an observed Lyα luminosity of 1043.92±0.05 erg s−1 is the most luminous Lyα emitter ever found at z > 6 and is spatially extended (∼16 kpc). “CR7” reveals a narrow Lyα line with 266 ± 15 km s−1 FWHM, being detected in the near-infrared (NIR) (rest-frame UV; β = −2.3 ± 0.1) and in IRAC/Spitzer. We detect a narrow He II 1640 Å emission line (6σ, FWHM = 130 ± 30 km s−1 ) in CR7 which can explain the clear excess seen in the J-band photometry (EW0 ∼ 80 Å). We find no other emission lines from the UV to the NIR in our X-SHOOTER spectra (He II/O III] 1663 Å > 3 and He II/C III] 1908 Å > 2.5). We conclude that CR7 is best explained by a combination of a PopIII-like population, which dominates the rest-frame UV and the nebular emission, and a more normal stellar population, which presumably dominates the mass. Hubble Space Telescope/WFC3 observations show that the light is indeed spatially separated between a very blue component, coincident with Lyα and He II emission, and two red components (∼5 kpc away), which dominate the mass. Our findings are consistent with theoretical predictions of a PopIII wave, with PopIII star formation migrating away from the original sites of star formation.' acknowledgement: We thank the anonymous reviewer for useful and constructive comments and suggestions which greatly improved the quality and clarity of our work. D.S. acknowledges financial support from the Netherlands Organisation for Scientific research (NWO) through a Veni fellowship, from FCT through a FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010), from FCT grant UID/FIS/04434/2013, and from LSF and LKBF. J.M. acknowledges the award of a Huygens PhD fellowship. H.R. acknowledges support from the ERC Advanced Investigator program NewClusters 321271. The authors thank Mark Dijkstra, Bhaskar Agarwal, Jarrett Johnson, Andrea Ferrara, Jarle Brinchmann, Rebecca Bowler, George Becker, Emma Curtis-Lake, Milos Milosavljevic, Raffaella Schneider, Paul Shapiro, and Erik Zackrisson for interesting, stimulating and helpful discussions. The authors are extremely grateful to ESO for the award of ESO DDT time (294.A-5018 and 294.A-5039) which allowed the spectroscopic confirmation of both sources and the detailed investigation of their nature. Observations are also based on data from W.M. Keck Observatory. The W.M. Keck Observatory is operated as a scientific partnership of Caltech, the University of California and the National Aeronautics and Space Administration. Based on observations obtained with MegaPrime/Megacam, a joint project of CFHT and CEA/IRFU, at the Canada–France–Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de lUnivers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at Terapix available at the Canadian Astronomy Data Centre as part of the Canada–France–Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO programme IDs 294.A-5018, 294.A-5039, and 179.A-2005, and on data products produced by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium. The authors acknowledge the award of service time (SW2014b20) on the William Herschel Telescope (WHT). WHT and its service programme are operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. article_processing_charge: No article_type: original author: - first_name: David full_name: Sobral, David last_name: Sobral - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: Behnam full_name: Darvish, Behnam last_name: Darvish - first_name: Daniel full_name: Schaerer, Daniel last_name: Schaerer - first_name: Bahram full_name: Mobasher, Bahram last_name: Mobasher - first_name: Huub full_name: Röttgering, Huub last_name: Röttgering - first_name: Sérgio full_name: Santos, Sérgio last_name: Santos - first_name: Shoubaneh full_name: Hemmati, Shoubaneh last_name: Hemmati citation: ama: 'Sobral D, Matthee JJ, Darvish B, et al. Evidence for PopIII-like stellar populations in the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation. The Astrophysical Journal. 2015;808(2):139. doi:10.1088/0004-637X/808/2/139' apa: 'Sobral, D., Matthee, J. J., Darvish, B., Schaerer, D., Mobasher, B., Röttgering, H., … Hemmati, S. (2015). Evidence for PopIII-like stellar populations in the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation. The Astrophysical Journal. IOP Publishing. https://doi.org/10.1088/0004-637X/808/2/139' chicago: 'Sobral, David, Jorryt J Matthee, Behnam Darvish, Daniel Schaerer, Bahram Mobasher, Huub Röttgering, Sérgio Santos, and Shoubaneh Hemmati. “Evidence for PopIII-like Stellar Populations in the Most Luminous Lyα Emitters at the Epoch of Reionisation: Spectroscopic Confirmation.” The Astrophysical Journal. IOP Publishing, 2015. https://doi.org/10.1088/0004-637X/808/2/139.' ieee: 'D. Sobral et al., “Evidence for PopIII-like stellar populations in the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation,” The Astrophysical Journal, vol. 808, no. 2. IOP Publishing, p. 139, 2015.' ista: 'Sobral D, Matthee JJ, Darvish B, Schaerer D, Mobasher B, Röttgering H, Santos S, Hemmati S. 2015. Evidence for PopIII-like stellar populations in the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation. The Astrophysical Journal. 808(2), 139.' mla: 'Sobral, David, et al. “Evidence for PopIII-like Stellar Populations in the Most Luminous Lyα Emitters at the Epoch of Reionisation: Spectroscopic Confirmation.” The Astrophysical Journal, vol. 808, no. 2, IOP Publishing, 2015, p. 139, doi:10.1088/0004-637X/808/2/139.' short: D. Sobral, J.J. Matthee, B. Darvish, D. Schaerer, B. Mobasher, H. Röttgering, S. Santos, S. Hemmati, The Astrophysical Journal 808 (2015) 139. date_created: 2022-07-07T09:00:58Z date_published: 2015-07-28T00:00:00Z date_updated: 2022-08-18T10:30:13Z day: '28' doi: 10.1088/0004-637X/808/2/139 extern: '1' external_id: arxiv: - '1504.01734' intvolume: ' 808' issue: '2' keyword: - Space and Planetary Science - Astronomy and Astrophysics - dark ages - reionization - 'first stars – early universe – galaxies: evolution' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1504.01734 month: '07' oa: 1 oa_version: Preprint page: '139' publication: The Astrophysical Journal publication_identifier: eissn: - 1538-4357 issn: - 0004-637X publication_status: published publisher: IOP Publishing quality_controlled: '1' scopus_import: '1' status: public title: 'Evidence for PopIII-like stellar populations in the most luminous Lyα emitters at the epoch of reionisation: Spectroscopic confirmation' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 808 year: '2015' ... --- _id: '11580' abstract: - lang: eng text: 'We present results from the largest contiguous narrow-band survey in the near-infrared. We have used the wide-field infrared camera/Canada–France–Hawaii Telescope and the lowOH2 filter (1.187 ± 0.005 μm) to survey ≈10 deg2 of contiguous extragalactic sky in the SA22 field. A total of ∼6000 candidate emission-line galaxies are found. We use deep ugrizJK data to obtain robust photometric redshifts. We combine our data with the High-redshift(Z) Emission Line Survey (HiZELS), explore spectroscopic surveys (VVDS, VIPERS) and obtain our own spectroscopic follow-up with KMOS, FMOS and MOSFIRE to derive large samples of high-redshift emission-line selected galaxies: 3471 Hα emitters at z = 0.8, 1343 [O III] + Hβ emitters at z = 1.4 and 572 [O II] emitters at z = 2.2. We probe comoving volumes of >106 Mpc3 and find significant overdensities, including an 8.5σ (spectroscopically confirmed) overdensity of Hα emitters at z = 0.81. We derive Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4, 2.2, respectively, and present implications for future surveys such as Euclid. Our uniquely large volumes/areas allow us to subdivide the samples in thousands of randomized combinations of areas and provide a robust empirical measurement of sample/cosmic variance. We show that surveys for star-forming/emission-line galaxies at a depth similar to ours can only overcome cosmic-variance (errors <10 per cent) if they are based on volumes >5 × 105 Mpc3; errors on L* and ϕ* due to sample (cosmic) variance on surveys probing ∼104 and ∼105 Mpc3 are typically very high: ∼300 and ∼40–60 per cent, respectively.' acknowledgement: The authors wish to thank the anonymous reviewer for many helpful comments and suggestions which greatly improved the clarity and quality of this work. DS acknowledges financial support from the Netherlands Organization for Scientific research (NWO) through a Veni fellowship, from FCT through an FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010), from FCT grant PEst-OE/FIS/UI2751/2014, and from LSF and LKBF. JM acknowledges the award of a Huygens PhD fellowship. PNB is grateful for support from STFC. IRS acknowledges support from STFC, a Leverhulme Fellowship, the ERC Advanced Investigator programme DUSTYGAL and a Royal Society/Wolfson Merit Award. BMJ acknowledges support from the ERC-StG grant EGGS-278202. The Dark Cosmology Centre is funded by the DNRF. The Dark Cosmology Centre is funded by the DNRF. JWK acknowledges support from the National Research Foundation of Korea (NRF) grant, no. 2008-0060544, funded by the Korea government (MSIP). JPS acknowledges support from STFC (ST/I001573/1). JC acknowledges support from the FCT-IF grant IF/01154/2012/CP0189/CT0010. The work was only possible due to OPTICON/FP7 and the invaluable access that it granted to the CFHT telescope. We would also like to acknowledge the excellent work done by CFHT staff in conducting the observations in service mode, and on delivering truly excellent data. We are also tremendously thankful to Kentaro Aoki for the incredible support while observing at Subaru with FMOS, and also to the Keck staff for the help with the observations with MOSFIRE. This work is based on observations obtained with WIRCam on the CFHT, OPTICON programme 2011B/029, 2012A019 and 2012B/016. Based on observations made with ESO telescopes at the La Silla Paranal Observatory under programmes IDs 60.A-9460 (data can be accessed through the ESO data archive), 087.A 0337 and 089.A-0965. Based on observations done with FMOS on Subaru under programme S14A-084, and on MOSFIRE/Keck observations under programme U066M. Part of the data on which this analysis is based are available from Sobral et al. (2013a). Dedicated to the memory of C. M. Sobral (1953-2014). article_processing_charge: No article_type: original author: - first_name: D. full_name: Sobral, D. last_name: Sobral - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: P. N. full_name: Best, P. N. last_name: Best - first_name: I. full_name: Smail, I. last_name: Smail - first_name: A. A. full_name: Khostovan, A. A. last_name: Khostovan - first_name: B. full_name: Milvang-Jensen, B. last_name: Milvang-Jensen - first_name: J.-W. full_name: Kim, J.-W. last_name: Kim - first_name: J. full_name: Stott, J. last_name: Stott - first_name: J. full_name: Calhau, J. last_name: Calhau - first_name: H. full_name: Nayyeri, H. last_name: Nayyeri - first_name: B. full_name: Mobasher, B. last_name: Mobasher citation: ama: 'Sobral D, Matthee JJ, Best PN, et al. CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and 2.2 . Monthly Notices of the Royal Astronomical Society. 2015;451(3):2303-2323. doi:10.1093/mnras/stv1076' apa: 'Sobral, D., Matthee, J. J., Best, P. N., Smail, I., Khostovan, A. A., Milvang-Jensen, B., … Mobasher, B. (2015). CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and 2.2 . Monthly Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/stv1076' chicago: 'Sobral, D., Jorryt J Matthee, P. N. Best, I. Smail, A. A. Khostovan, B. Milvang-Jensen, J.-W. Kim, et al. “CF-HiZELS, an ∼10 Deg2 Emission-Line Survey with Spectroscopic Follow-up: Hα, [O III] + Hβ and [O II] Luminosity Functions at z = 0.8, 1.4 and 2.2 .” Monthly Notices of the Royal Astronomical Society. Oxford University Press, 2015. https://doi.org/10.1093/mnras/stv1076.' ieee: 'D. Sobral et al., “CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and 2.2 ,” Monthly Notices of the Royal Astronomical Society, vol. 451, no. 3. Oxford University Press, pp. 2303–2323, 2015.' ista: 'Sobral D, Matthee JJ, Best PN, Smail I, Khostovan AA, Milvang-Jensen B, Kim J-W, Stott J, Calhau J, Nayyeri H, Mobasher B. 2015. CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and 2.2 . Monthly Notices of the Royal Astronomical Society. 451(3), 2303–2323.' mla: 'Sobral, D., et al. “CF-HiZELS, an ∼10 Deg2 Emission-Line Survey with Spectroscopic Follow-up: Hα, [O III] + Hβ and [O II] Luminosity Functions at z = 0.8, 1.4 and 2.2 .” Monthly Notices of the Royal Astronomical Society, vol. 451, no. 3, Oxford University Press, 2015, pp. 2303–23, doi:10.1093/mnras/stv1076.' short: D. Sobral, J.J. Matthee, P.N. Best, I. Smail, A.A. Khostovan, B. Milvang-Jensen, J.-W. Kim, J. Stott, J. Calhau, H. Nayyeri, B. Mobasher, Monthly Notices of the Royal Astronomical Society 451 (2015) 2303–2323. date_created: 2022-07-14T09:02:22Z date_published: 2015-08-11T00:00:00Z date_updated: 2022-08-19T08:23:18Z day: '11' doi: 10.1093/mnras/stv1076 extern: '1' external_id: arxiv: - '1502.06602' intvolume: ' 451' issue: '3' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: evolution' - 'galaxies: formation' - 'galaxies: luminosity function' - mass function - 'cosmology: observations' - early Universe - large-scale structure of Universe language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1502.06602 month: '08' oa: 1 oa_version: Preprint page: 2303-2323 publication: Monthly Notices of the Royal Astronomical Society publication_identifier: eissn: - 1365-2966 issn: - 0035-8711 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: 'CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up: Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and 2.2 ' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 451 year: '2015' ... --- _id: '11581' abstract: - lang: eng text: Using wide-field narrow-band surveys, we provide a new measurement of the z = 6.6 Lymanα emitter (LAE) luminosity function (LF), which constraints the bright end for the first time. We use a combination of archival narrow-band NB921 data in UDS and new NB921 measurements in SA22 and COSMOS/UltraVISTA, all observed with the Subaru telescope, with a total area of ∼5 deg2. We exclude lower redshift interlopers by using broad-band optical and near-infrared photometry and also exclude three supernovae with data split over multiple epochs. Combining the UDS and COSMOS samples, we find no evolution of the bright end of the Lyα LF between z = 5.7 and 6.6, which is supported by spectroscopic follow-up, and conclude that sources with Himiko-like luminosity are not as rare as previously thought, with number densities of ∼1.5 × 10−5 Mpc−3. Combined with our wide-field SA22 measurements, our results indicate a non-Schechter-like bright end of the LF at z = 6.6 and a different evolution of observed faint and bright LAEs, overcoming cosmic variance. This differential evolution is also seen in the spectroscopic follow-up of UV-selected galaxies and is now also confirmed for LAEs, and we argue that it may be an effect of reionization. Using a toy model, we show that such differential evolution of the LF is expected, since brighter sources are able to ionize their surroundings earlier, such that Lyα photons are able to escape. Our targets are excellent candidates for detailed follow-up studies and provide the possibility to give a unique view on the earliest stages in the formation of galaxies and reionization process. acknowledgement: "We thank the anonymous referee for the comments and suggestions which have improved the quality of this work. We thank Masami Ouchi for his useful comments on an earlier version of this paper. JM acknowledges the support of a Huygens PhD fellowship from Leiden University and is thankful for the hospitality of the Center for Astronomy and Astrophysics of the University of Lisbon where part of this research has been done. DS acknowledges financial support from the Netherlands Organization for Scientific research (NWO) through a Veni fellowship, from FCT through a FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010) and from FCT grant PEstOE/FIS/UI2751/2014. HR acknowledges support from the ERC Advanced Investigator programme NewClusters 321271. We acknowledge the award of ESO DDT time (294.A-5018) for providing the possibility of a timely publication of this work.\r\nBased on observations with the Subaru Telescope (Programme IDs: our observations: S14A-086; archival: S05B-027, S06A-025, S06B-010, S07A-013, S07B-008, S08B-008 and S09A-017) and the W.M. Keck Observatory. The Subaru telescope is operated by the National Astronomical Observatory of Japan. The W.M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 294.A-5018. Based on observations obtained with MegaPrime/Megacam, a joint project of CFHT and CEA/IRFU, at the Canada–France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l’Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at Terapix available at the Canadian Astronomy Data Centre as part of the CFHT Legacy Survey, a collaborative project of NRC and CNRS. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO programme ID 179.A-2005 and on data products produced by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium.\r\nIn addition to the CFHT-LS and COSMOS-UltraVISTA surveys, we are grateful for the excellent data sets from the UKIRT-DXS, SXDF and S-COSMOS survey teams, without these legacy surveys, this research would have been impossible. We have benefited greatly from the public available programming language PYTHON, including the NUMPY, MATPLOTLIB, PYFITS, SCIPY and ASTROPY packages, the astronomical imaging tools SEXTRACTOR, SWARP and SCAMP and the indispensable TOPCAT analysis tool (Taylor 2013)" article_processing_charge: No article_type: original author: - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: David full_name: Sobral, David last_name: Sobral - first_name: Sérgio full_name: Santos, Sérgio last_name: Santos - first_name: Huub full_name: Röttgering, Huub last_name: Röttgering - first_name: Behnam full_name: Darvish, Behnam last_name: Darvish - first_name: Bahram full_name: Mobasher, Bahram last_name: Mobasher citation: ama: 'Matthee JJ, Sobral D, Santos S, Röttgering H, Darvish B, Mobasher B. Identification of the brightest Lyα emitters at z = 6.6: implications for the evolution of the luminosity function in the reionization era. Monthly Notices of the Royal Astronomical Society. 2015;451(1):400-417. doi:10.1093/mnras/stv947' apa: 'Matthee, J. J., Sobral, D., Santos, S., Röttgering, H., Darvish, B., & Mobasher, B. (2015). Identification of the brightest Lyα emitters at z = 6.6: implications for the evolution of the luminosity function in the reionization era. Monthly Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/stv947' chicago: 'Matthee, Jorryt J, David Sobral, Sérgio Santos, Huub Röttgering, Behnam Darvish, and Bahram Mobasher. “Identification of the Brightest Lyα Emitters at z = 6.6: Implications for the Evolution of the Luminosity Function in the Reionization Era.” Monthly Notices of the Royal Astronomical Society. Oxford University Press, 2015. https://doi.org/10.1093/mnras/stv947.' ieee: 'J. J. Matthee, D. Sobral, S. Santos, H. Röttgering, B. Darvish, and B. Mobasher, “Identification of the brightest Lyα emitters at z = 6.6: implications for the evolution of the luminosity function in the reionization era,” Monthly Notices of the Royal Astronomical Society, vol. 451, no. 1. Oxford University Press, pp. 400–417, 2015.' ista: 'Matthee JJ, Sobral D, Santos S, Röttgering H, Darvish B, Mobasher B. 2015. Identification of the brightest Lyα emitters at z = 6.6: implications for the evolution of the luminosity function in the reionization era. Monthly Notices of the Royal Astronomical Society. 451(1), 400–417.' mla: 'Matthee, Jorryt J., et al. “Identification of the Brightest Lyα Emitters at z = 6.6: Implications for the Evolution of the Luminosity Function in the Reionization Era.” Monthly Notices of the Royal Astronomical Society, vol. 451, no. 1, Oxford University Press, 2015, pp. 400–17, doi:10.1093/mnras/stv947.' short: J.J. Matthee, D. Sobral, S. Santos, H. Röttgering, B. Darvish, B. Mobasher, Monthly Notices of the Royal Astronomical Society 451 (2015) 400–417. date_created: 2022-07-14T11:57:03Z date_published: 2015-07-21T00:00:00Z date_updated: 2022-08-19T08:25:25Z day: '21' doi: 10.1093/mnras/stv947 extern: '1' external_id: arxiv: - '1502.07355' intvolume: ' 451' issue: '1' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1502.07355 month: '07' oa: 1 oa_version: Preprint page: 400-417 publication: Monthly Notices of the Royal Astronomical Society publication_identifier: eissn: - 1365-2966 issn: - 0035-8711 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: 'Identification of the brightest Lyα emitters at z = 6.6: implications for the evolution of the luminosity function in the reionization era' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 451 year: '2015' ... --- _id: '11579' abstract: - lang: eng text: CR7 is the brightest z = 6.6 Ly α emitter (LAE) known to date, and spectroscopic follow-up by Sobral et al. suggests that CR7 might host Population (Pop) III stars. We examine this interpretation using cosmological hydrodynamical simulations. Several simulated galaxies show the same ‘Pop III wave’ pattern observed in CR7. However, to reproduce the extreme CR7 Ly α/He II1640 line luminosities (⁠Lα/HeII⁠) a top-heavy initial mass function and a massive ( ≳ 107 M⊙) Pop III burst with age ≲ 2 Myr are required. Assuming that the observed properties of Ly α and He II emission are typical for Pop III, we predict that in the COSMOS/UDS/SA22 fields, 14 out of the 30 LAEs at z = 6.6 with Lα > 1043.3 erg s−1 should also host Pop III stars producing an observable LHeII≳1042.7ergs−1⁠. As an alternate explanation, we explore the possibility that CR7 is instead powered by accretion on to a direct collapse black hole. Our model predicts Lα, LHeII⁠, and X-ray luminosities that are in agreement with the observations. In any case, the observed properties of CR7 indicate that this galaxy is most likely powered by sources formed from pristine gas. We propose that further X-ray observations can distinguish between the two above scenarios. acknowledgement: SS acknowledges support from the Netherlands Organization for Scientific research (NWO), VENI grant 639.041.233. RS acknowledges support from the European Research Council under the European Union (FP/2007-2013)/ERC grant agreement no. 306476. DS acknowledges (i) financial support from the NWO through a Veni fellowship and (ii) funding from FCT through a FCT Investigator Starting Grant and Start-up Grant (IF/01154/2012/CP0189/CT0010) and from FCT grant PEstOE/FIS/UI2751/2014. article_processing_charge: No article_type: original author: - first_name: A. full_name: Pallottini, A. last_name: Pallottini - first_name: A. full_name: Ferrara, A. last_name: Ferrara - first_name: F. full_name: Pacucci, F. last_name: Pacucci - first_name: S. full_name: Gallerani, S. last_name: Gallerani - first_name: S. full_name: Salvadori, S. last_name: Salvadori - first_name: R. full_name: Schneider, R. last_name: Schneider - first_name: D. full_name: Schaerer, D. last_name: Schaerer - first_name: D. full_name: Sobral, D. last_name: Sobral - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X citation: ama: 'Pallottini A, Ferrara A, Pacucci F, et al. The brightest Lyα emitter: Pop III or black hole? Monthly Notices of the Royal Astronomical Society. 2015;453(3):2465-2470. doi:10.1093/mnras/stv1795' apa: 'Pallottini, A., Ferrara, A., Pacucci, F., Gallerani, S., Salvadori, S., Schneider, R., … Matthee, J. J. (2015). The brightest Lyα emitter: Pop III or black hole? Monthly Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/stv1795' chicago: 'Pallottini, A., A. Ferrara, F. Pacucci, S. Gallerani, S. Salvadori, R. Schneider, D. Schaerer, D. Sobral, and Jorryt J Matthee. “The Brightest Lyα Emitter: Pop III or Black Hole?” Monthly Notices of the Royal Astronomical Society. Oxford University Press, 2015. https://doi.org/10.1093/mnras/stv1795.' ieee: 'A. Pallottini et al., “The brightest Lyα emitter: Pop III or black hole?,” Monthly Notices of the Royal Astronomical Society, vol. 453, no. 3. Oxford University Press, pp. 2465–2470, 2015.' ista: 'Pallottini A, Ferrara A, Pacucci F, Gallerani S, Salvadori S, Schneider R, Schaerer D, Sobral D, Matthee JJ. 2015. The brightest Lyα emitter: Pop III or black hole? Monthly Notices of the Royal Astronomical Society. 453(3), 2465–2470.' mla: 'Pallottini, A., et al. “The Brightest Lyα Emitter: Pop III or Black Hole?” Monthly Notices of the Royal Astronomical Society, vol. 453, no. 3, Oxford University Press, 2015, pp. 2465–70, doi:10.1093/mnras/stv1795.' short: A. Pallottini, A. Ferrara, F. Pacucci, S. Gallerani, S. Salvadori, R. Schneider, D. Schaerer, D. Sobral, J.J. Matthee, Monthly Notices of the Royal Astronomical Society 453 (2015) 2465–2470. date_created: 2022-07-14T08:58:36Z date_published: 2015-11-01T00:00:00Z date_updated: 2022-08-19T08:19:23Z day: '01' doi: 10.1093/mnras/stv1795 extern: '1' external_id: arxiv: - '1506.07173' intvolume: ' 453' issue: '3' keyword: - Space and Planetary Science - Astronomy and Astrophysics - black hole physics - 'stars: Population III' - 'galaxies: high-redshift' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1506.07173 month: '11' oa: 1 oa_version: Preprint page: 2465-2470 publication: Monthly Notices of the Royal Astronomical Society publication_identifier: eissn: - 1365-2966 issn: - 0035-8711 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: 'The brightest Lyα emitter: Pop III or black hole?' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 453 year: '2015' ... --- _id: '11668' abstract: - lang: eng text: "We study multiple keyword sponsored search auctions with budgets. Each keyword has multiple ad slots with a click-through rate. The bidders have additive valuations, which are linear in the click-through rates, and budgets, which are restricting their overall payments. Additionally, the number of slots per keyword assigned to a bidder is bounded.\r\n\r\nWe show the following results: (1) We give the first mechanism for multiple keywords, where click-through rates differ among slots. Our mechanism is incentive compatible in expectation, individually rational in expectation, and Pareto optimal. (2) We study the combinatorial setting, where each bidder is only interested in a subset of the keywords. We give an incentive compatible, individually rational, Pareto-optimal, and deterministic mechanism for identical click-through rates. (3) We give an impossibility result for incentive compatible, individually rational, Pareto-optimal, and deterministic mechanisms for bidders with diminishing marginal valuations." article_number: '2' article_processing_charge: No article_type: original author: - first_name: Riccardo full_name: Colini-Baldeschi, Riccardo last_name: Colini-Baldeschi - first_name: Stefano full_name: Leonardi, Stefano last_name: Leonardi - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Martin full_name: Starnberger, Martin last_name: Starnberger citation: ama: Colini-Baldeschi R, Leonardi S, Henzinger MH, Starnberger M. On multiple keyword sponsored search auctions with budgets. ACM Transactions on Economics and Computation. 2015;4(1). doi:10.1145/2818357 apa: Colini-Baldeschi, R., Leonardi, S., Henzinger, M. H., & Starnberger, M. (2015). On multiple keyword sponsored search auctions with budgets. ACM Transactions on Economics and Computation. Association for Computing Machinery. https://doi.org/10.1145/2818357 chicago: Colini-Baldeschi, Riccardo, Stefano Leonardi, Monika H Henzinger, and Martin Starnberger. “On Multiple Keyword Sponsored Search Auctions with Budgets.” ACM Transactions on Economics and Computation. Association for Computing Machinery, 2015. https://doi.org/10.1145/2818357. ieee: R. Colini-Baldeschi, S. Leonardi, M. H. Henzinger, and M. Starnberger, “On multiple keyword sponsored search auctions with budgets,” ACM Transactions on Economics and Computation, vol. 4, no. 1. Association for Computing Machinery, 2015. ista: Colini-Baldeschi R, Leonardi S, Henzinger MH, Starnberger M. 2015. On multiple keyword sponsored search auctions with budgets. ACM Transactions on Economics and Computation. 4(1), 2. mla: Colini-Baldeschi, Riccardo, et al. “On Multiple Keyword Sponsored Search Auctions with Budgets.” ACM Transactions on Economics and Computation, vol. 4, no. 1, 2, Association for Computing Machinery, 2015, doi:10.1145/2818357. short: R. Colini-Baldeschi, S. Leonardi, M.H. Henzinger, M. Starnberger, ACM Transactions on Economics and Computation 4 (2015). date_created: 2022-07-27T11:54:56Z date_published: 2015-12-05T00:00:00Z date_updated: 2023-02-09T10:03:35Z day: '05' doi: 10.1145/2818357 extern: '1' intvolume: ' 4' issue: '1' keyword: - Algorithms - Economics - Clinching ascending auction - auctions with budgets - Sponsored search auctions language: - iso: eng main_file_link: - open_access: '1' url: http://eprints.cs.univie.ac.at/3510/ month: '12' oa: 1 oa_version: Submitted Version publication: ACM Transactions on Economics and Computation publication_identifier: eissn: - 2167-8383 issn: - 2167-8375 publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' scopus_import: '1' status: public title: On multiple keyword sponsored search auctions with budgets type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 4 year: '2015' ... --- _id: '11669' abstract: - lang: eng text: We study individual rational, Pareto-optimal, and incentive compatible mechanisms for auctions with heterogeneous items and budget limits. We consider settings with multiunit demand and additive valuations. For single-dimensional valuations we prove a positive result for randomized mechanisms, and a negative result for deterministic mechanisms. While the positive result allows for private budgets, the negative result is for public budgets. For multidimensional valuations and public budgets we prove an impossibility result that applies to deterministic and randomized mechanisms. Taken together this shows the power of randomization in certain settings with heterogeneous items, but it also shows its limitations. article_number: '4' article_processing_charge: No article_type: original author: - first_name: Paul full_name: Dütting, Paul last_name: Dütting - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Martin full_name: Starnberger, Martin last_name: Starnberger citation: ama: Dütting P, Henzinger MH, Starnberger M. Auctions for heterogeneous items and budget limits. ACM Transactions on Economics and Computation. 2015;4(1). doi:10.1145/2818351 apa: Dütting, P., Henzinger, M. H., & Starnberger, M. (2015). Auctions for heterogeneous items and budget limits. ACM Transactions on Economics and Computation. Association for Computing Machinery. https://doi.org/10.1145/2818351 chicago: Dütting, Paul, Monika H Henzinger, and Martin Starnberger. “Auctions for Heterogeneous Items and Budget Limits.” ACM Transactions on Economics and Computation. Association for Computing Machinery, 2015. https://doi.org/10.1145/2818351. ieee: P. Dütting, M. H. Henzinger, and M. Starnberger, “Auctions for heterogeneous items and budget limits,” ACM Transactions on Economics and Computation, vol. 4, no. 1. Association for Computing Machinery, 2015. ista: Dütting P, Henzinger MH, Starnberger M. 2015. Auctions for heterogeneous items and budget limits. ACM Transactions on Economics and Computation. 4(1), 4. mla: Dütting, Paul, et al. “Auctions for Heterogeneous Items and Budget Limits.” ACM Transactions on Economics and Computation, vol. 4, no. 1, 4, Association for Computing Machinery, 2015, doi:10.1145/2818351. short: P. Dütting, M.H. Henzinger, M. Starnberger, ACM Transactions on Economics and Computation 4 (2015). date_created: 2022-07-27T12:09:15Z date_published: 2015-12-05T00:00:00Z date_updated: 2022-09-09T12:08:37Z day: '05' doi: 10.1145/2818351 extern: '1' external_id: arxiv: - '1209.6448' intvolume: ' 4' issue: '1' keyword: - Algorithmic game theory - auction theory - Clinching auction - Pareto optimality - Budget limits language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1209.6448 month: '12' oa: 1 oa_version: Preprint publication: ACM Transactions on Economics and Computation publication_identifier: eissn: - 2167-8383 issn: - 2167-8375 publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' scopus_import: '1' status: public title: Auctions for heterogeneous items and budget limits type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 4 year: '2015' ... --- _id: '11670' abstract: - lang: eng text: Auctions are widely used on the Web. Applications range from sponsored search to platforms such as eBay. In these and in many other applications the auctions in use are single-/multi-item auctions with unit demand. The main drawback of standard mechanisms for this type of auctions, such as VCG and GSP, is the limited expressiveness that they offer to the bidders. The General Auction Mechanism (GAM) of Aggarwal et al. [2009] takes a first step toward addressing the problem of limited expressiveness by computing a bidder optimal, envy-free outcome for linear utility functions with identical slopes and a single discontinuity per bidder-item pair. We show that in many practical situations this does not suffice to adequately model the preferences of the bidders, and we overcome this problem by presenting the first mechanism for piecewise linear utility functions with nonidentical slopes and multiple discontinuities. Our mechanism runs in polynomial time. Like GAM it is incentive compatible for inputs that fulfill a certain nondegeneracy assumption, but our requirement is more general than the requirement of GAM. For discontinuous utility functions that are nondegenerate as well as for continuous utility functions the outcome of our mechanism is a competitive equilibrium. We also show how our mechanism can be used to compute approximately bidder optimal, envy-free outcomes for a general class of continuous utility functions via piecewise linear approximation. Finally, we prove hardness results for even more expressive settings. acknowledgement: We would like to thank Veronika Loitzenbauer and the anonymous referees for their valuable feedback. article_number: '1' article_processing_charge: No article_type: original author: - first_name: Paul full_name: Dütting, Paul last_name: Dütting - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Ingmar full_name: Weber, Ingmar last_name: Weber citation: ama: Dütting P, Henzinger MH, Weber I. An expressive mechanism for auctions on the web. ACM Transactions on Economics and Computation. 2015;4(1). doi:10.1145/2716312 apa: Dütting, P., Henzinger, M. H., & Weber, I. (2015). An expressive mechanism for auctions on the web. ACM Transactions on Economics and Computation. Association for Computing Machinery. https://doi.org/10.1145/2716312 chicago: Dütting, Paul, Monika H Henzinger, and Ingmar Weber. “An Expressive Mechanism for Auctions on the Web.” ACM Transactions on Economics and Computation. Association for Computing Machinery, 2015. https://doi.org/10.1145/2716312. ieee: P. Dütting, M. H. Henzinger, and I. Weber, “An expressive mechanism for auctions on the web,” ACM Transactions on Economics and Computation, vol. 4, no. 1. Association for Computing Machinery, 2015. ista: Dütting P, Henzinger MH, Weber I. 2015. An expressive mechanism for auctions on the web. ACM Transactions on Economics and Computation. 4(1), 1. mla: Dütting, Paul, et al. “An Expressive Mechanism for Auctions on the Web.” ACM Transactions on Economics and Computation, vol. 4, no. 1, 1, Association for Computing Machinery, 2015, doi:10.1145/2716312. short: P. Dütting, M.H. Henzinger, I. Weber, ACM Transactions on Economics and Computation 4 (2015). date_created: 2022-07-27T12:43:18Z date_published: 2015-12-02T00:00:00Z date_updated: 2023-02-09T10:08:41Z day: '02' doi: 10.1145/2716312 extern: '1' intvolume: ' 4' issue: '1' keyword: - Computational Mathematics - Marketing - Economics and Econometrics - Statistics and Probability - Computer Science (miscellaneous) language: - iso: eng month: '12' oa_version: None publication: ACM Transactions on Economics and Computation publication_identifier: eissn: - 2167-8383 issn: - 2167-8375 publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' scopus_import: '1' status: public title: An expressive mechanism for auctions on the web type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 4 year: '2015' ... --- _id: '11774' abstract: - lang: eng text: "Combinatorial auctions (CA) are a well-studied area in algorithmic mechanism design. However, contrary to the standard model, empirical studies suggest that a bidder’s valuation often does not depend solely on the goods assigned to him. For instance, in adwords auctions an advertiser might not want his ads to be displayed next to his competitors’ ads. In this paper, we propose and analyze several natural graph-theoretic models that incorporate such negative externalities, in which bidders form a directed conflict graph with maximum out-degree Δ. We design algorithms and truthful mechanisms for social welfare maximization that attain approximation ratios depending on Δ.\r\n\r\nFor CA, our results are twofold: (1) A lottery that eliminates conflicts by discarding bidders/items independent of the bids. It allows to apply any truthful \U0001D6FC-approximation mechanism for conflict-free valuations and yields an \U0001D4AA(\U0001D6FCΔ)-approximation mechanism. (2) For fractionally sub-additive valuations, we design a rounding algorithm via a novel combination of a semi-definite program and a linear program, resulting in a cone program; the approximation ratio is \U0001D4AA((ΔloglogΔ)/logΔ). The ratios are almost optimal given existing hardness results.\r\n\r\nFor adwords auctions, we present several algorithms for the most relevant scenario when the number of items is small. In particular, we design a truthful mechanism with approximation ratio \U0001D45C(Δ) when the number of items is only logarithmic in the number of bidders." alternative_title: - LNCS article_processing_charge: No author: - first_name: Yun Kuen full_name: Cheung, Yun Kuen last_name: Cheung - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Martin full_name: Hoefer, Martin last_name: Hoefer - first_name: Martin full_name: Starnberger, Martin last_name: Starnberger citation: ama: 'Cheung YK, Henzinger MH, Hoefer M, Starnberger M. Combinatorial auctions with conflict-based externalities. In: 11th International Conference on Web and Internet Economics. Vol 9470. Springer Nature; 2015:230–243. doi:10.1007/978-3-662-48995-6_17' apa: 'Cheung, Y. K., Henzinger, M. H., Hoefer, M., & Starnberger, M. (2015). Combinatorial auctions with conflict-based externalities. In 11th International Conference on Web and Internet Economics (Vol. 9470, pp. 230–243). Amsterdam, Netherlands: Springer Nature. https://doi.org/10.1007/978-3-662-48995-6_17' chicago: Cheung, Yun Kuen, Monika H Henzinger, Martin Hoefer, and Martin Starnberger. “Combinatorial Auctions with Conflict-Based Externalities.” In 11th International Conference on Web and Internet Economics, 9470:230–243. Springer Nature, 2015. https://doi.org/10.1007/978-3-662-48995-6_17. ieee: Y. K. Cheung, M. H. Henzinger, M. Hoefer, and M. Starnberger, “Combinatorial auctions with conflict-based externalities,” in 11th International Conference on Web and Internet Economics, Amsterdam, Netherlands, 2015, vol. 9470, pp. 230–243. ista: 'Cheung YK, Henzinger MH, Hoefer M, Starnberger M. 2015. Combinatorial auctions with conflict-based externalities. 11th International Conference on Web and Internet Economics. WINE: International Conference on Web and Internet Economics, LNCS, vol. 9470, 230–243.' mla: Cheung, Yun Kuen, et al. “Combinatorial Auctions with Conflict-Based Externalities.” 11th International Conference on Web and Internet Economics, vol. 9470, Springer Nature, 2015, pp. 230–243, doi:10.1007/978-3-662-48995-6_17. short: Y.K. Cheung, M.H. Henzinger, M. Hoefer, M. Starnberger, in:, 11th International Conference on Web and Internet Economics, Springer Nature, 2015, pp. 230–243. conference: end_date: 2015-12-12 location: Amsterdam, Netherlands name: 'WINE: International Conference on Web and Internet Economics' start_date: 2015-12-09 date_created: 2022-08-08T13:54:32Z date_published: 2015-12-09T00:00:00Z date_updated: 2023-02-10T09:08:30Z day: '09' doi: 10.1007/978-3-662-48995-6_17 extern: '1' external_id: arxiv: - '1509.09147' intvolume: ' 9470' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.1509.09147 month: '12' oa: 1 oa_version: Preprint page: 230–243 publication: 11th International Conference on Web and Internet Economics publication_identifier: eisbn: - '9783662489956' isbn: - '9783662489949' issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Combinatorial auctions with conflict-based externalities type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9470 year: '2015' ... --- _id: '11773' abstract: - lang: eng text: "Ad exchanges are an emerging platform for trading advertisement slots on the web with billions of dollars revenue per year. Every time a user visits a web page, the publisher of that web page can ask an ad exchange to auction off the ad slots on this page to determine which advertisements are shown at which price. Due to the high volume of traffic, ad networks typically act as mediators for individual advertisers at ad exchanges. If multiple advertisers in an ad network are interested in the ad slots of the same auction, the ad network might use a “local” auction to resell the obtained ad slots among its advertisers.\r\n\r\nIn this work we want to deepen the theoretical understanding of these new markets by analyzing them from the viewpoint of combinatorial auctions. Prior work studied mostly single-item auctions, while we allow the advertisers to express richer preferences over multiple items. We develop a game-theoretic model for the entanglement of the central auction at the ad exchange with the local auctions at the ad networks. We consider the incentives of all three involved parties and suggest a three-party competitive equilibrium, an extension of the Walrasian equilibrium that ensures envy-freeness for all participants. We show the existence of a three-party competitive equilibrium and a polynomial-time algorithm to find one for gross-substitute bidder valuations." alternative_title: - LNCS article_processing_charge: No author: - first_name: Oren full_name: Ben-Zwi, Oren last_name: Ben-Zwi - first_name: Monika H full_name: Henzinger, Monika H id: 540c9bbd-f2de-11ec-812d-d04a5be85630 last_name: Henzinger orcid: 0000-0002-5008-6530 - first_name: Veronika full_name: Loitzenbauer, Veronika last_name: Loitzenbauer citation: ama: 'Ben-Zwi O, Henzinger MH, Loitzenbauer V. Ad exchange: Envy-free auctions with mediators. In: 11th International Conference on Web and Internet Economics. Vol 9470. Springer Nature; 2015:104–117. doi:10.1007/978-3-662-48995-6_8' apa: 'Ben-Zwi, O., Henzinger, M. H., & Loitzenbauer, V. (2015). Ad exchange: Envy-free auctions with mediators. In 11th International Conference on Web and Internet Economics (Vol. 9470, pp. 104–117). Amsterdam, Netherlands: Springer Nature. https://doi.org/10.1007/978-3-662-48995-6_8' chicago: 'Ben-Zwi, Oren, Monika H Henzinger, and Veronika Loitzenbauer. “Ad Exchange: Envy-Free Auctions with Mediators.” In 11th International Conference on Web and Internet Economics, 9470:104–117. Springer Nature, 2015. https://doi.org/10.1007/978-3-662-48995-6_8.' ieee: 'O. Ben-Zwi, M. H. Henzinger, and V. Loitzenbauer, “Ad exchange: Envy-free auctions with mediators,” in 11th International Conference on Web and Internet Economics, Amsterdam, Netherlands, 2015, vol. 9470, pp. 104–117.' ista: 'Ben-Zwi O, Henzinger MH, Loitzenbauer V. 2015. Ad exchange: Envy-free auctions with mediators. 11th International Conference on Web and Internet Economics. WINE: International Conference on Web and Internet Economics, LNCS, vol. 9470, 104–117.' mla: 'Ben-Zwi, Oren, et al. “Ad Exchange: Envy-Free Auctions with Mediators.” 11th International Conference on Web and Internet Economics, vol. 9470, Springer Nature, 2015, pp. 104–117, doi:10.1007/978-3-662-48995-6_8.' short: O. Ben-Zwi, M.H. Henzinger, V. Loitzenbauer, in:, 11th International Conference on Web and Internet Economics, Springer Nature, 2015, pp. 104–117. conference: end_date: 2015-09-12 location: Amsterdam, Netherlands name: 'WINE: International Conference on Web and Internet Economics' start_date: 2015-09-09 date_created: 2022-08-08T13:33:56Z date_published: 2015-12-09T00:00:00Z date_updated: 2023-02-10T09:06:23Z day: '09' doi: 10.1007/978-3-662-48995-6_8 extern: '1' external_id: arxiv: - '1604.05562' intvolume: ' 9470' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.1604.05562 month: '12' oa: 1 oa_version: Preprint page: 104–117 publication: 11th International Conference on Web and Internet Economics publication_identifier: eisbn: - '9783662489956' isbn: - '9783662489949' issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: 'Ad exchange: Envy-free auctions with mediators' type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9470 year: '2015' ...