TY - CONF AB - In this work we consider the list-decodability and list-recoverability of arbitrary q-ary codes, for all integer values of q ≥ 2. A code is called (p,L)_q-list-decodable if every radius pn Hamming ball contains less than L codewords; (p,𝓁,L)_q-list-recoverability is a generalization where we place radius pn Hamming balls on every point of a combinatorial rectangle with side length 𝓁 and again stipulate that there be less than L codewords. Our main contribution is to precisely calculate the maximum value of p for which there exist infinite families of positive rate (p,𝓁,L)_q-list-recoverable codes, the quantity we call the zero-rate threshold. Denoting this value by p_*, we in fact show that codes correcting a p_*+ε fraction of errors must have size O_ε(1), i.e., independent of n. Such a result is typically referred to as a "Plotkin bound." To complement this, a standard random code with expurgation construction shows that there exist positive rate codes correcting a p_*-ε fraction of errors. We also follow a classical proof template (typically attributed to Elias and Bassalygo) to derive from the zero-rate threshold other tradeoffs between rate and decoding radius for list-decoding and list-recovery. Technically, proving the Plotkin bound boils down to demonstrating the Schur convexity of a certain function defined on the q-simplex as well as the convexity of a univariate function derived from it. We remark that an earlier argument claimed similar results for q-ary list-decoding; however, we point out that this earlier proof is flawed. AU - Resch, Nicolas AU - Yuan, Chen AU - Zhang, Yihan ID - 14083 SN - 1868-8969 T2 - 50th International Colloquium on Automata, Languages, and Programming TI - Zero-rate thresholds and new capacity bounds for list-decoding and list-recovery VL - 261 ER - TY - JOUR AB - The influence of structural modifications on the catalytic activity of carbon materials is poorly understood. A collection of carbonaceous materials with different pore networks and high nitrogen content was characterized and used to catalyze four reactions to deduce structure–activity relationships. The CO2 cycloaddition and Knoevenagel reaction depend on Lewis basic sites (electron-rich nitrogen species). The absence of large conjugated carbon domains resulting from the introduction of large amounts of nitrogen in the carbon network is responsible for poor redox activity, as observed through the catalytic reduction of nitrobenzene with hydrazine and the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine using hydroperoxide. The material with the highest activity towards Lewis acid catalysis (in the hydrolysis of (dimethoxymethyl)benzene to benzaldehyde) is the most effective for small molecule activation and presents the highest concentration of electron-poor nitrogen species. AU - Lepre, Enrico AU - Rat, Sylvain AU - Cavedon, Cristian AU - Seeberger, Peter H. AU - Pieber, Bartholomäus AU - Antonietti, Markus AU - López‐Salas, Nieves ID - 12922 IS - 2 JF - Angewandte Chemie International Edition KW - General Chemistry KW - Catalysis SN - 1433-7851 TI - Catalytic properties of high nitrogen content carbonaceous materials VL - 62 ER - TY - JOUR AB - In previous work, we identified a population of 38 cool and luminous variable stars in the Magellanic Clouds and examined 11 in detail in order to classify them as either Thorne–Żytkow objects (TŻOs; red supergiants with a neutron star cores) or super-asymptotic giant branch (sAGB) stars (the most massive stars that will not undergo core collapse). This population includes HV 2112, a peculiar star previously considered in other works to be either a TŻO or high-mass asymptotic giant branch (AGB) star. Here we continue this investigation, using the kinematic and radio environments and local star formation history of these stars to place constraints on the age of the progenitor systems and the presence of past supernovae. These stars are not associated with regions of recent star formation, and we find no evidence of past supernovae at their locations. Finally, we also assess the presence of heavy elements and lithium in their spectra compared to red supergiants. We find strong absorption in Li and s-process elements compared to RSGs in most of the sample, consistent with sAGB nucleosynthesis, while HV 2112 shows additional strong lines associated with TŻO nucleosynthesis. Coupled with our previous mass estimates, the results are consistent with the stars being massive (∼4–6.5 M⊙) or sAGB (∼6.5–12 M⊙) stars in the thermally pulsing phase, providing crucial observations of the transition between low- and high-mass stellar populations. HV 2112 is more ambiguous; it could either be a maximally massive sAGB star, or a TŻO if the minimum mass for stability extends down to ≲13 M⊙. AU - O‘Grady, Anna J. G. AU - Drout, Maria R. AU - Gaensler, B. M. AU - Kochanek, C. S. AU - Neugent, Kathryn F. AU - Doherty, Carolyn L. AU - Speagle, Joshua S. AU - Shappee, B. J. AU - Rauch, Michael AU - Götberg, Ylva Louise Linsdotter AU - Ludwig, Bethany AU - Thompson, Todd A. ID - 13450 IS - 1 JF - The Astrophysical Journal KW - Space and Planetary Science KW - Astronomy and Astrophysics SN - 0004-637X TI - Cool, luminous, and highly variable stars in the Magellanic Clouds. II. Spectroscopic and environmental analysis of Thorne–Żytkow object and super-AGB star candidates VL - 943 ER - TY - JOUR AB - Stars strongly impact their environment, and shape structures on all scales throughout the universe, in a process known as "feedback." Due to the complexity of both stellar evolution and the physics of larger astrophysical structures, there remain many unanswered questions about how feedback operates and what we can learn about stars by studying their imprint on the wider universe. In this white paper, we summarize discussions from the Lorentz Center meeting "Bringing Stellar Evolution and Feedback Together" in 2022 April and identify key areas where further dialog can bring about radical changes in how we view the relationship between stars and the universe they live in. AU - Geen, Sam AU - Agrawal, Poojan AU - Crowther, Paul A. AU - Keller, B. W. AU - de Koter, Alex AU - Keszthelyi, Zsolt AU - van de Voort, Freeke AU - Ali, Ahmad A. AU - Backs, Frank AU - Bonne, Lars AU - Brugaletta, Vittoria AU - Derkink, Annelotte AU - Ekström, Sylvia AU - Fichtner, Yvonne A. AU - Grassitelli, Luca AU - Götberg, Ylva Louise Linsdotter AU - Higgins, Erin R. AU - Laplace, Eva AU - You Liow, Kong AU - Lorenzo, Marta AU - McLeod, Anna F. AU - Meynet, Georges AU - Newsome, Megan AU - André Oliva, G. AU - Ramachandran, Varsha AU - Rey, Martin P. AU - Rieder, Steven AU - Romano-Díaz, Emilio AU - Sabhahit, Gautham AU - Sander, Andreas A. C. AU - Sarwar, Rafia AU - Stinshoff, Hanno AU - Stoop, Mitchel AU - Szécsi, Dorottya AU - Trebitsch, Maxime AU - Vink, Jorick S. AU - Winch, Ethan ID - 13449 IS - 1044 JF - Publications of the Astronomical Society of the Pacific KW - Space and Planetary Science KW - Astronomy and Astrophysics SN - 0004-6280 TI - Bringing stellar evolution and feedback together: Summary of proposals from the Lorentz Center workshop VL - 135 ER - TY - JOUR AB - Thorne–Żytkow objects (TŻO) are potential end products of the merger of a neutron star with a non-degenerate star. In this work, we have computed the first grid of evolutionary models of TŻOs with the MESA stellar evolution code. With these models, we predict several observational properties of TŻOs, including their surface temperatures and luminosities, pulsation periods, and nucleosynthetic products. We expand the range of possible TŻO solutions to cover 3.45≲log(Teff/K)≲3.65 and 4.85≲log(L/L⊙)≲5.5⁠. Due to the much higher densities our TŻOs reach compared to previous models, if TŻOs form we expect them to be stable over a larger mass range than previously predicted, without exhibiting a gap in their mass distribution. Using the GYRE stellar pulsation code we show that TŻOs should have fundamental pulsation periods of 1000–2000 d, and period ratios of ≈0.2–0.3. Models computed with a large 399 isotope fully coupled nuclear network show a nucleosynthetic signal that is different to previously predicted. We propose a new nucleosynthetic signal to determine a star’s status as a TŻO: the isotopologues 44TiO2 and 44TiO⁠, which will have a shift in their spectral features as compared to stable titanium-containing molecules. We find that in the local Universe (∼SMC metallicities and above) TŻOs show little heavy metal enrichment, potentially explaining the difficulty in finding TŻOs to-date. AU - Farmer, R AU - Renzo, M AU - Götberg, Ylva Louise Linsdotter AU - Bellinger, E AU - Justham, S AU - de Mink, S E ID - 14104 IS - 2 JF - Monthly Notices of the Royal Astronomical Society KW - Space and Planetary Science KW - Astronomy and Astrophysics SN - 0035-8711 TI - Observational predictions for Thorne–Żytkow objects VL - 524 ER - TY - JOUR AB - Characterizing and controlling entanglement in quantum materials is crucial for the development of next-generation quantum technologies. However, defining a quantifiable figure of merit for entanglement in macroscopic solids is theoretically and experimentally challenging. At equilibrium the presence of entanglement can be diagnosed by extracting entanglement witnesses from spectroscopic observables and a nonequilibrium extension of this method could lead to the discovery of novel dynamical phenomena. Here, we propose a systematic approach to quantify the time-dependent quantum Fisher information and entanglement depth of transient states of quantum materials with time-resolved resonant inelastic x-ray scattering. Using a quarter-filled extended Hubbard model as an example, we benchmark the efficiency of this approach and predict a light-enhanced many-body entanglement due to the proximity to a phase boundary. Our work sets the stage for experimentally witnessing and controlling entanglement in light-driven quantum materials via ultrafast spectroscopic measurements. AU - Hales, Jordyn AU - Bajpai, Utkarsh AU - Liu, Tongtong AU - Baykusheva, Denitsa Rangelova AU - Li, Mingda AU - Mitrano, Matteo AU - Wang, Yao ID - 13989 JF - Nature Communications KW - General Physics and Astronomy KW - General Biochemistry KW - Genetics and Molecular Biology KW - General Chemistry KW - Multidisciplinary TI - Witnessing light-driven entanglement using time-resolved resonant inelastic X-ray scattering VL - 14 ER - TY - JOUR AB - Many-body entanglement in condensed matter systems can be diagnosed from equilibrium response functions through the use of entanglement witnesses and operator-specific quantum bounds. Here, we investigate the applicability of this approach for detecting entangled states in quantum systems driven out of equilibrium. We use a multipartite entanglement witness, the quantum Fisher information, to study the dynamics of a paradigmatic fermion chain undergoing a time-dependent change of the Coulomb interaction. Our results show that the quantum Fisher information is able to witness distinct signatures of multipartite entanglement both near and far from equilibrium that are robust against decoherence. We discuss implications of these findings for probing entanglement in light-driven quantum materials with time-resolved optical and x-ray scattering methods. AU - Baykusheva, Denitsa Rangelova AU - Kalthoff, Mona H. AU - Hofmann, Damian AU - Claassen, Martin AU - Kennes, Dante M. AU - Sentef, Michael A. AU - Mitrano, Matteo ID - 13990 IS - 10 JF - Physical Review Letters KW - General Physics and Astronomy SN - 0031-9007 TI - Witnessing nonequilibrium entanglement dynamics in a strongly correlated fermionic chain VL - 130 ER - TY - JOUR AB - Models for same-material contact electrification in granular media often rely on a local charge-driving parameter whose spatial variations lead to a stochastic origin for charge exchange. Measuring the charge transfer from individual granular spheres after contacts with substrates of the same material, we find instead a “global” charging behavior, coherent over the sample’s whole surface. Cleaning and baking samples fully resets charging magnitude and direction, which indicates the underlying global parameter is not intrinsic to the material, but acquired from its history. Charging behavior is randomly and irreversibly affected by changes in relative humidity, hinting at a mechanism where adsorbates, in particular, water, are fundamental to the charge-transfer process. AU - Grosjean, Galien M AU - Waitukaitis, Scott R ID - 12697 IS - 9 JF - Physical Review Letters KW - General Physics KW - Electrostatics KW - Triboelectricity KW - Soft Matter KW - Acoustic Levitation KW - Granular Materials SN - 0031-9007 TI - Single-collision statistics reveal a global mechanism driven by sample history for contact electrification in granular media VL - 130 ER - TY - JOUR AB - Observations of individual massive stars, super-luminous supernovae, gamma-ray bursts, and gravitational wave events involving spectacular black hole mergers indicate that the low-metallicity Universe is fundamentally different from our own Galaxy. Many transient phenomena will remain enigmatic until we achieve a firm understanding of the physics and evolution of massive stars at low metallicity (Z). The Hubble Space Telescope has devoted 500 orbits to observing ∼250 massive stars at low Z in the ultraviolet (UV) with the COS and STIS spectrographs under the ULLYSES programme. The complementary X-Shooting ULLYSES (XShootU) project provides an enhanced legacy value with high-quality optical and near-infrared spectra obtained with the wide-wavelength coverage X-shooter spectrograph at ESO’s Very Large Telescope. We present an overview of the XShootU project, showing that combining ULLYSES UV and XShootU optical spectra is critical for the uniform determination of stellar parameters such as effective temperature, surface gravity, luminosity, and abundances, as well as wind properties such as mass-loss rates as a function of Z. As uncertainties in stellar and wind parameters percolate into many adjacent areas of astrophysics, the data and modelling of the XShootU project is expected to be a game changer for our physical understanding of massive stars at low Z. To be able to confidently interpret James Webb Space Telescope spectra of the first stellar generations, the individual spectra of low-Z stars need to be understood, which is exactly where XShootU can deliver. AU - Vink, Jorick S. AU - Mehner, A. AU - Crowther, P. A. AU - Fullerton, A. AU - Garcia, M. AU - Martins, F. AU - Morrell, N. AU - Oskinova, L. M. AU - St-Louis, N. AU - ud-Doula, A. AU - Sander, A. A. C. AU - Sana, H. AU - Bouret, J.-C. AU - Kubátová, B. AU - Marchant, P. AU - Martins, L. P. AU - Wofford, A. AU - van Loon, J. Th. AU - Grace Telford, O. AU - Götberg, Ylva Louise Linsdotter AU - Bowman, D. M. AU - Erba, C. AU - Kalari, V. M. AU - Abdul-Masih, M. AU - Alkousa, T. AU - Backs, F. AU - Barbosa, C. L. AU - Berlanas, S. R. AU - Bernini-Peron, M. AU - Bestenlehner, J. M. AU - Blomme, R. AU - Bodensteiner, J. AU - Brands, S. A. AU - Evans, C. J. AU - David-Uraz, A. AU - Driessen, F. A. AU - Dsilva, K. AU - Geen, S. AU - Gómez-González, V. M. A. AU - Grassitelli, L. AU - Hamann, W.-R. AU - Hawcroft, C. AU - Herrero, A. AU - Higgins, E. R. AU - John Hillier, D. AU - Ignace, R. AU - Istrate, A. G. AU - Kaper, L. AU - Kee, N. D. AU - Kehrig, C. AU - Keszthelyi, Z. AU - Klencki, J. AU - de Koter, A. AU - Kuiper, R. AU - Laplace, E. AU - Larkin, C. J. K. AU - Lefever, R. R. AU - Leitherer, C. AU - Lennon, D. J. AU - Mahy, L. AU - Maíz Apellániz, J. AU - Maravelias, G. AU - Marcolino, W. AU - McLeod, A. F. AU - de Mink, S. E. AU - Najarro, F. AU - Oey, M. S. AU - Parsons, T. N. AU - Pauli, D. AU - Pedersen, M. G. AU - Prinja, R. K. AU - Ramachandran, V. AU - Ramírez-Tannus, M. C. AU - Sabhahit, G. N. AU - Schootemeijer, A. AU - Reyero Serantes, S. AU - Shenar, T. AU - Stringfellow, G. S. AU - Sudnik, N. AU - Tramper, F. AU - Wang, L. ID - 14103 JF - Astronomy & Astrophysics KW - Space and Planetary Science KW - Astronomy and Astrophysics SN - 0004-6361 TI - X-shooting ULLYSES: Massive stars at low metallicity. I. Project description VL - 675 ER - TY - THES AB - About a 100 years ago, we discovered that our universe is inherently noisy, that is, measuring any physical quantity with a precision beyond a certain point is not possible because of an omnipresent inherent noise. We call this - the quantum noise. Certain physical processes allow this quantum noise to get correlated in conjugate physical variables. These quantum correlations can be used to go beyond the potential of our inherently noisy universe and obtain a quantum advantage over the classical applications. Quantum noise being inherent also means that, at the fundamental level, the physical quantities are not well defined and therefore, objects can stay in multiple states at the same time. For example, the position of a particle not being well defined means that the particle is in multiple positions at the same time. About 4 decades ago, we started exploring the possibility of using objects which can be in multiple states at the same time to increase the dimensionality in computation. Thus, the field of quantum computing was born. We discovered that using quantum entanglement, a property closely related to quantum correlations, can be used to speed up computation of certain problems, such as factorisation of large numbers, faster than any known classical algorithm. Thus began the pursuit to make quantum computers a reality. Till date, we have explored quantum control over many physical systems including photons, spins, atoms, ions and even simple circuits made up of superconducting material. However, there persists one ubiquitous theme. The more readily a system interacts with an external field or matter, the more easily we can control it. But this also means that such a system can easily interact with a noisy environment and quickly lose its coherence. Consequently, such systems like electron spins need to be protected from the environment to ensure the longevity of their coherence. Other systems like nuclear spins are naturally protected as they do not interact easily with the environment. But, due to the same reason, it is harder to interact with such systems. After decades of experimentation with various systems, we are convinced that no one type of quantum system would be the best for all the quantum applications. We would need hybrid systems which are all interconnected - much like the current internet where all sorts of devices can all talk to each other - but now for quantum devices. A quantum internet. Optical photons are the best contenders to carry information for the quantum internet. They can carry quantum information cheaply and without much loss - the same reasons which has made them the backbone of our current internet. Following this direction, many systems, like trapped ions, have already demonstrated successful quantum links over a large distances using optical photons. However, some of the most promising contenders for quantum computing which are based on microwave frequencies have been left behind. This is because high energy optical photons can adversely affect fragile low-energy microwave systems. In this thesis, we present substantial progress on this missing quantum link between microwave and optics using electrooptical nonlinearities in lithium niobate. The nonlinearities are enhanced by using resonant cavities for all the involved modes leading to observation of strong direct coupling between optical and microwave frequencies. With this strong coupling we are not only able to achieve almost 100\% internal conversion efficiency with low added noise, thus presenting a quantum-enabled transducer, but also we are able to observe novel effects such as cooling of a microwave mode using optics. The strong coupling regime also leads to direct observation of dynamical backaction effect between microwave and optical frequencies which are studied in detail here. Finally, we also report first observation of microwave-optics entanglement in form of two-mode squeezed vacuum squeezed 0.7dB below vacuum level. With this new bridge between microwave and optics, the microwave-based quantum technologies can finally be a part of a quantum network which is based on optical photons - putting us one step closer to a future with quantum internet. AU - Sahu, Rishabh ID - 13175 KW - quantum optics KW - electrooptics KW - quantum networks KW - quantum communication KW - transduction SN - 2663 - 337X TI - Cavity quantum electrooptics ER -