---
_id: '7791'
abstract:
- lang: eng
text: Extending a result of Milena Radnovic and Serge Tabachnikov, we establish
conditionsfor two different non-symmetric norms to define the same billiard reflection
law.
acknowledgement: AA was supported by European Research Council (ERC) under the European
Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 78818
Alpha). RK was supported by the Federal professorship program Grant 1.456.2016/1.4
and the Russian Foundation for Basic Research Grants 18-01-00036 and 19-01-00169.
Open access funding provided by Institute of Science and Technology (IST Austria).
The authors thank Alexey Balitskiy, Milena Radnović, and Serge Tabachnikov for useful
discussions.
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Arseniy
full_name: Akopyan, Arseniy
id: 430D2C90-F248-11E8-B48F-1D18A9856A87
last_name: Akopyan
orcid: 0000-0002-2548-617X
- first_name: Roman
full_name: Karasev, Roman
last_name: Karasev
citation:
ama: Akopyan A, Karasev R. When different norms lead to same billiard trajectories?
European Journal of Mathematics. 2022;8(4):1309-1312. doi:10.1007/s40879-020-00405-0
apa: Akopyan, A., & Karasev, R. (2022). When different norms lead to same billiard
trajectories? European Journal of Mathematics. Springer Nature. https://doi.org/10.1007/s40879-020-00405-0
chicago: Akopyan, Arseniy, and Roman Karasev. “When Different Norms Lead to Same
Billiard Trajectories?” European Journal of Mathematics. Springer Nature,
2022. https://doi.org/10.1007/s40879-020-00405-0.
ieee: A. Akopyan and R. Karasev, “When different norms lead to same billiard trajectories?,”
European Journal of Mathematics, vol. 8, no. 4. Springer Nature, pp. 1309–1312,
2022.
ista: Akopyan A, Karasev R. 2022. When different norms lead to same billiard trajectories?
European Journal of Mathematics. 8(4), 1309–1312.
mla: Akopyan, Arseniy, and Roman Karasev. “When Different Norms Lead to Same Billiard
Trajectories?” European Journal of Mathematics, vol. 8, no. 4, Springer
Nature, 2022, pp. 1309–12, doi:10.1007/s40879-020-00405-0.
short: A. Akopyan, R. Karasev, European Journal of Mathematics 8 (2022) 1309–1312.
date_created: 2020-05-03T22:00:48Z
date_published: 2022-12-01T00:00:00Z
date_updated: 2024-02-22T15:58:42Z
day: '01'
ddc:
- '510'
department:
- _id: HeEd
doi: 10.1007/s40879-020-00405-0
ec_funded: 1
external_id:
arxiv:
- '1912.12685'
file:
- access_level: open_access
checksum: f53e71fd03744075adcd0b8fc1b8423d
content_type: application/pdf
creator: dernst
date_created: 2020-05-04T10:33:42Z
date_updated: 2020-07-14T12:48:03Z
file_id: '7796'
file_name: 2020_EuropMathematics_Akopyan.pdf
file_size: 263926
relation: main_file
file_date_updated: 2020-07-14T12:48:03Z
has_accepted_license: '1'
intvolume: ' 8'
issue: '4'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '12'
oa: 1
oa_version: Published Version
page: 1309 - 1312
project:
- _id: 266A2E9E-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '788183'
name: Alpha Shape Theory Extended
- _id: B67AFEDC-15C9-11EA-A837-991A96BB2854
name: IST Austria Open Access Fund
publication: European Journal of Mathematics
publication_identifier:
eissn:
- 2199-6768
issn:
- 2199-675X
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: When different norms lead to same billiard trajectories?
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 8
year: '2022'
...
---
_id: '10608'
abstract:
- lang: eng
text: We consider infinite-dimensional properties in coarse geometry for hyperspaces
consisting of finite subsets of metric spaces with the Hausdorff metric. We see
that several infinite-dimensional properties are preserved by taking the hyperspace
of subsets with at most n points. On the other hand, we prove that, if a metric
space contains a sequence of long intervals coarsely, then its hyperspace of finite
subsets is not coarsely embeddable into any uniformly convex Banach space. As
a corollary, the hyperspace of finite subsets of the real line is not coarsely
embeddable into any uniformly convex Banach space. It is also shown that every
(not necessarily bounded geometry) metric space with straight finite decomposition
complexity has metric sparsification property.
acknowledgement: We would like to thank the referees for their careful reading and
the comments that improved our work. The third named author would like to thank
the Division of Mathematics, Physics and Earth Sciences of the Graduate School of
Science and Engineering of Ehime University and the second named author for hosting
his visit in June 2018. Open access funding provided by Institute of Science and
Technology (IST Austria).
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Thomas
full_name: Weighill, Thomas
last_name: Weighill
- first_name: Takamitsu
full_name: Yamauchi, Takamitsu
last_name: Yamauchi
- first_name: Nicolò
full_name: Zava, Nicolò
id: c8b3499c-7a77-11eb-b046-aa368cbbf2ad
last_name: Zava
citation:
ama: Weighill T, Yamauchi T, Zava N. Coarse infinite-dimensionality of hyperspaces
of finite subsets. European Journal of Mathematics. 2021. doi:10.1007/s40879-021-00515-3
apa: Weighill, T., Yamauchi, T., & Zava, N. (2021). Coarse infinite-dimensionality
of hyperspaces of finite subsets. European Journal of Mathematics. Springer
Nature. https://doi.org/10.1007/s40879-021-00515-3
chicago: Weighill, Thomas, Takamitsu Yamauchi, and Nicolò Zava. “Coarse Infinite-Dimensionality
of Hyperspaces of Finite Subsets.” European Journal of Mathematics. Springer
Nature, 2021. https://doi.org/10.1007/s40879-021-00515-3.
ieee: T. Weighill, T. Yamauchi, and N. Zava, “Coarse infinite-dimensionality of
hyperspaces of finite subsets,” European Journal of Mathematics. Springer
Nature, 2021.
ista: Weighill T, Yamauchi T, Zava N. 2021. Coarse infinite-dimensionality of hyperspaces
of finite subsets. European Journal of Mathematics.
mla: Weighill, Thomas, et al. “Coarse Infinite-Dimensionality of Hyperspaces of
Finite Subsets.” European Journal of Mathematics, Springer Nature, 2021,
doi:10.1007/s40879-021-00515-3.
short: T. Weighill, T. Yamauchi, N. Zava, European Journal of Mathematics (2021).
date_created: 2022-01-09T23:01:27Z
date_published: 2021-12-30T00:00:00Z
date_updated: 2022-01-10T08:36:55Z
day: '30'
ddc:
- '500'
department:
- _id: HeEd
doi: 10.1007/s40879-021-00515-3
file:
- access_level: open_access
checksum: c435dcfa1ad3aadc5cdd7366bc7f4e98
content_type: application/pdf
creator: cchlebak
date_created: 2022-01-10T08:33:22Z
date_updated: 2022-01-10T08:33:22Z
file_id: '10610'
file_name: 2021_EuJournalMath_Weighill.pdf
file_size: 384908
relation: main_file
success: 1
file_date_updated: 2022-01-10T08:33:22Z
has_accepted_license: '1'
language:
- iso: eng
month: '12'
oa: 1
oa_version: Published Version
publication: European Journal of Mathematics
publication_identifier:
eissn:
- 2199-6768
issn:
- 2199-675X
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Coarse infinite-dimensionality of hyperspaces of finite subsets
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2021'
...
---
_id: '8538'
abstract:
- lang: eng
text: We prove some recent experimental observations of Dan Reznik concerning periodic
billiard orbits in ellipses. For example, the sum of cosines of the angles of
a periodic billiard polygon remains constant in the 1-parameter family of such
polygons (that exist due to the Poncelet porism). In our proofs, we use geometric
and complex analytic methods.
acknowledgement: " This paper would not be written if not for Dan Reznik’s curiosity
and persistence; we are very grateful to him. We also thank R. Garcia and J. Koiller
for interesting discussions. It is a pleasure to thank the Mathematical Institute
of the University of Heidelberg for its stimulating atmosphere. ST thanks M. Bialy
for interesting discussions and the Tel Aviv\r\nUniversity for its invariable hospitality.
AA was supported by European Research Council (ERC) under the European Union’s Horizon
2020 research and innovation programme (grant agreement No 78818 Alpha). RS is supported
by NSF Grant DMS-1807320. ST was supported by NSF grant DMS-1510055 and SFB/TRR
191."
article_processing_charge: No
article_type: original
author:
- first_name: Arseniy
full_name: Akopyan, Arseniy
id: 430D2C90-F248-11E8-B48F-1D18A9856A87
last_name: Akopyan
orcid: 0000-0002-2548-617X
- first_name: Richard
full_name: Schwartz, Richard
last_name: Schwartz
- first_name: Serge
full_name: Tabachnikov, Serge
last_name: Tabachnikov
citation:
ama: Akopyan A, Schwartz R, Tabachnikov S. Billiards in ellipses revisited. European
Journal of Mathematics. 2020. doi:10.1007/s40879-020-00426-9
apa: Akopyan, A., Schwartz, R., & Tabachnikov, S. (2020). Billiards in ellipses
revisited. European Journal of Mathematics. Springer Nature. https://doi.org/10.1007/s40879-020-00426-9
chicago: Akopyan, Arseniy, Richard Schwartz, and Serge Tabachnikov. “Billiards in
Ellipses Revisited.” European Journal of Mathematics. Springer Nature,
2020. https://doi.org/10.1007/s40879-020-00426-9.
ieee: A. Akopyan, R. Schwartz, and S. Tabachnikov, “Billiards in ellipses revisited,”
European Journal of Mathematics. Springer Nature, 2020.
ista: Akopyan A, Schwartz R, Tabachnikov S. 2020. Billiards in ellipses revisited.
European Journal of Mathematics.
mla: Akopyan, Arseniy, et al. “Billiards in Ellipses Revisited.” European Journal
of Mathematics, Springer Nature, 2020, doi:10.1007/s40879-020-00426-9.
short: A. Akopyan, R. Schwartz, S. Tabachnikov, European Journal of Mathematics
(2020).
date_created: 2020-09-20T22:01:38Z
date_published: 2020-09-09T00:00:00Z
date_updated: 2021-12-02T15:10:17Z
day: '09'
department:
- _id: HeEd
doi: 10.1007/s40879-020-00426-9
ec_funded: 1
external_id:
arxiv:
- '2001.02934'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2001.02934
month: '09'
oa: 1
oa_version: Preprint
project:
- _id: 266A2E9E-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '788183'
name: Alpha Shape Theory Extended
publication: European Journal of Mathematics
publication_identifier:
eissn:
- 2199-6768
issn:
- 2199-675X
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Billiards in ellipses revisited
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2020'
...
---
_id: '441'
article_processing_charge: No
article_type: original
author:
- first_name: Nikita
full_name: Kalinin, Nikita
last_name: Kalinin
- first_name: Mikhail
full_name: Shkolnikov, Mikhail
id: 35084A62-F248-11E8-B48F-1D18A9856A87
last_name: Shkolnikov
orcid: 0000-0002-4310-178X
citation:
ama: Kalinin N, Shkolnikov M. Tropical formulae for summation over a part of SL(2,Z).
European Journal of Mathematics. 2019;5(3):909–928. doi:10.1007/s40879-018-0218-0
apa: Kalinin, N., & Shkolnikov, M. (2019). Tropical formulae for summation over
a part of SL(2,Z). European Journal of Mathematics. Springer Nature. https://doi.org/10.1007/s40879-018-0218-0
chicago: Kalinin, Nikita, and Mikhail Shkolnikov. “Tropical Formulae for Summation
over a Part of SL(2,Z).” European Journal of Mathematics. Springer Nature,
2019. https://doi.org/10.1007/s40879-018-0218-0.
ieee: N. Kalinin and M. Shkolnikov, “Tropical formulae for summation over a part
of SL(2,Z),” European Journal of Mathematics, vol. 5, no. 3. Springer Nature,
pp. 909–928, 2019.
ista: Kalinin N, Shkolnikov M. 2019. Tropical formulae for summation over a part
of SL(2,Z). European Journal of Mathematics. 5(3), 909–928.
mla: Kalinin, Nikita, and Mikhail Shkolnikov. “Tropical Formulae for Summation over
a Part of SL(2,Z).” European Journal of Mathematics, vol. 5, no. 3, Springer
Nature, 2019, pp. 909–928, doi:10.1007/s40879-018-0218-0.
short: N. Kalinin, M. Shkolnikov, European Journal of Mathematics 5 (2019) 909–928.
date_created: 2018-12-11T11:46:29Z
date_published: 2019-09-15T00:00:00Z
date_updated: 2021-01-12T07:56:46Z
day: '15'
department:
- _id: TaHa
doi: 10.1007/s40879-018-0218-0
ec_funded: 1
external_id:
arxiv:
- '1711.02089'
intvolume: ' 5'
issue: '3'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1711.02089
month: '09'
oa: 1
oa_version: Preprint
page: 909–928
project:
- _id: 25681D80-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '291734'
name: International IST Postdoc Fellowship Programme
publication: European Journal of Mathematics
publication_identifier:
eissn:
- 2199-6768
issn:
- 2199-675X
publication_status: published
publisher: Springer Nature
publist_id: '7382'
quality_controlled: '1'
scopus_import: 1
status: public
title: Tropical formulae for summation over a part of SL(2,Z)
type: journal_article
user_id: D865714E-FA4E-11E9-B85B-F5C5E5697425
volume: 5
year: '2019'
...