BGU Math: TBAMarch 4, 11:10—12:00, 2021, Online2021-02-11T10:51:49+02:002021-02-11T10:51:24+02:00BGU MathNattalie Tamam: Effective equidistribution of horospherical flows in infinite volumeMarch 11, 16:00—17:00, 2021, Online2021-03-11T17:46:31+02:002021-02-11T10:52:06+02:00BGU MathNattalie Tamamhttps://www.math.ucsd.edu/~natamam/University of California, San Diego<div class="mathjax"><p>Horospherical flows in homogeneous spaces have been studied intensively over the last several decades and have many surprising applications in various fields. Many basic results are under the assumption that the volume of the space is finite, which is crucial as many basic ergodic theorems fail in the setting of an infinite measure space. In the talk we will discuss the infinite volume setting, and specifically, when can we expect horospherical orbits to equidistribute. Our goal will be to provide an effective equidistribution result, with polynomial rate, for horospherical orbits in the frame bundle of certain infinite volume hyperbolic manifolds. This is a joint work with Jacqueline Warren.</p></div>Yuqing Frank Lin: A multiplicative ergodic theorem for von Neumann algebra valued cocyclesMarch 18, 11:10—12:00, 2021, Online2021-03-18T16:41:24+02:002021-02-11T10:52:18+02:00BGU MathYuqing Frank Linhttps://web.ma.utexas.edu/users/ylin/Ben-Gurion University<div class="mathjax"><p>Oseledets’ multiplicative ergodic theorem (MET) is an important tool in smooth ergodic theory. It may be viewed as a generalization of Birkhoff’s pointwise ergodic theorem where numbers are replaced by matrices and arithmetic means are replaced by geometric means. Starting from Ruelle in 1982, many infinite-dimensional generalizations of the MET have been produced; however, these results assume quasi-compactness conditions and so do not deal with continuous spectrum. In a different direction Karlsson-Margulis obtained a geometric generalization of the MET, which we apply in our work to obtain an MET with operators in von Neumann algebras with semi-finite trace. We do not assume any compactness conditions on the operators. Joint work with Lewis Bowen and Ben Hayes.</p></div>: Passover breakMarch 25, 11:10—12:00, 2021, -1012021-02-11T10:53:34+02:002021-02-11T10:53:19+02:00BGU Math: Passover breakApril 1, 11:10—12:00, 2021, -1012021-02-11T10:53:55+02:002021-02-11T10:53:55+02:00BGU Math: Holocaust Memorial DayApril 8, 11:10—12:00, 2021, -1012021-02-11T10:54:47+02:002021-02-11T10:54:47+02:00BGU Math: Memorial day for Israel's fallenApril 15, 11:10—12:00, 2021, -1012021-02-11T10:56:05+02:002021-02-11T10:56:05+02:00BGU MathZohar Reizis: Random walks on finite partite simplicial complexesApril 22, 11:10—12:00, 2021, Online2021-04-19T09:26:16+03:002021-02-11T10:56:33+02:00BGU MathZohar ReizisBen-Gurion University<div class="mathjax"><p>Random walks on graphs (and their spectral analysis) is an extensively explored topic with many applications in pure math and computer science. Recently, there has been much interest (by both the math and the CS communities) in the study of random walks on simplicial complexes as a high dimensional generalization on random walks on graphs.
In this talk, we consider the spectrum of random walks on finite partite simplicial complexes and show how with a general decomposition theorem on Hilbert spaces we can improve previous works. All the definitions will be given. This is a joint work with Izhar Oppenheim.</p></div>Nishant Chandgotia: TBAApril 29, 11:10—12:00, 2021, Online2021-02-11T21:24:02+02:002021-02-11T10:57:04+02:00BGU MathNishant Chandgotiahttp://math.huji.ac.il/~nishant/The Hebrew University Tsachik Gelander: TBAMay 6, 11:10—12:00, 2021, Online2021-02-19T12:35:09+02:002021-02-11T10:57:46+02:00BGU Math Tsachik Gelanderhttps://www.weizmann.ac.il/pages/search/people?language=english&single=1&person_id=48373Weizmann InstituteFaustin Adiceam: TBAMay 13, 11:10—12:00, 2021, Online2021-04-05T18:11:44+03:002021-02-11T10:57:58+02:00BGU MathFaustin Adiceamhttps://sites.google.com/site/fadiceammaths/The University of ManchesterDoron Puder: TBAMay 20, 11:10—12:00, 2021, Online2021-04-05T09:39:27+03:002021-02-11T10:58:08+02:00BGU MathDoron Puderhttps://sites.google.com/site/doronpuder/Tel-Aviv UniversityYiftach Dayan: TBAMay 27, 11:10—12:00, 2021, Online2021-04-06T14:34:23+03:002021-02-11T10:58:22+02:00BGU MathYiftach DayanTel-Aviv UniversityDaren Wei: Slow entropy of higher rank abelian unipotent actionsJune 3, 11:10—12:00, 2021, Online2021-04-07T14:05:44+03:002021-02-11T10:58:47+02:00BGU MathDaren Weihttps://sites.google.com/view/darenweimath/The Hebrew University<div class="mathjax"><p>We study slow entropy invariants for abelian unipotent actions U on any finite volume homogeneous space <span class="kdmath">$G/\Gamma$</span>. For every such action we show that the topological complexity can be computed directly from the dimension of a special decomposition of Lie(G) induced by Lie(U). Moreover, we are able to show that the metric complexity of the action coincides with its topological complexity, which provides a classification of these actions in isomorphic class. As a corollary, we obtain that the complexity of any abelian horocyclic action is only related to the dimension of G. This generalizes our previous rank one results from to higher rank abelian actions. This is a joint work with Adam Kanigowski, Philipp Kunde and Kurt Vinhage.</p></div>Henna Koivusalo: TBAJune 10, 11:10—12:00, 2021, Online2021-04-06T17:13:01+03:002021-02-11T10:58:59+02:00BGU MathHenna Koivusalohttps://people.maths.bris.ac.uk/~te20281/University of Bristol: TBAJune 17, 11:10—12:00, 2021, Online2021-02-11T10:59:17+02:002021-02-11T10:59:17+02:00BGU Math