Text only print
Full screen print
Seminar information archive
Seminar information archive ～03/28｜Today's seminar 03/29 | Future seminars 03/30～
Tokyo-Nagoya Algebra Seminar
16:30-18:00 Online
Please see the URL below for details on the online seminar.
Yasuaki Gyoda (Nagoya University)
Positive cluster complex and $\tau$-tilting complex (Japanese)
Please see the URL below for details on the online seminar.
Yasuaki Gyoda (Nagoya University)
Positive cluster complex and $\tau$-tilting complex (Japanese)
[ Abstract ]
In cluster algebra theory, cluster complexes are actively studied as simplicial complexes, which represent the structure of a seed and its mutations. In this talk, I will discuss a certain subcomplex, called positive cluster complex, of a cluster complex. This is a subcomplex whose vertex set consists of all cluster variables except for those in the initial seed. I will also introduce another simplicial complex in this talk - the tau-tilting complex, which has vertices given by all indecomposable tau-rigid modules, and simplices given by basic tau-rigid modules. In the case of a cluster-tilted algebra, it turns out that a tau-tilting complex corresponds to some positive cluster complex. Due to this fact, we can investigate the structure of a tau-tilting complex of tau-tilting finite type by using the tools of cluster algebra theory. This is joint work with Haruhisa Enomoto.
In cluster algebra theory, cluster complexes are actively studied as simplicial complexes, which represent the structure of a seed and its mutations. In this talk, I will discuss a certain subcomplex, called positive cluster complex, of a cluster complex. This is a subcomplex whose vertex set consists of all cluster variables except for those in the initial seed. I will also introduce another simplicial complex in this talk - the tau-tilting complex, which has vertices given by all indecomposable tau-rigid modules, and simplices given by basic tau-rigid modules. In the case of a cluster-tilted algebra, it turns out that a tau-tilting complex corresponds to some positive cluster complex. Due to this fact, we can investigate the structure of a tau-tilting complex of tau-tilting finite type by using the tools of cluster algebra theory. This is joint work with Haruhisa Enomoto.
2020/10/26
Seminar on Geometric Complex Analysis
10:30-12:00 Online
HATTORI Kota (Keio University)
Spectral convergence in geometric quantization
[ Reference URL ]
https://zoom.us/meeting/register/tJ0vcu2rrDIqG9Rv5AT0Mpi37urIkJ1IRldB
HATTORI Kota (Keio University)
Spectral convergence in geometric quantization
[ Reference URL ]
https://zoom.us/meeting/register/tJ0vcu2rrDIqG9Rv5AT0Mpi37urIkJ1IRldB
2020/10/22
Operator Algebra Seminars
16:45-18:15 Online
Hiroyasu Hamada (National Institute of Technology, Sasebo College)
$C^*$-algebras generated by multiplication operators and composition operators by functions with self-similar branches
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Hiroyasu Hamada (National Institute of Technology, Sasebo College)
$C^*$-algebras generated by multiplication operators and composition operators by functions with self-similar branches
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Information Mathematics Seminar
16:50-18:35 Room #オンライン(Zoom) (Graduate School of Math. Sci. Bldg.)
Hiroshi Fujiwara (BroadBand Tower, Inc.)
Think about a zero trust from information security 10 size menace 2020 (Japanese)
https://forms.gle/Uhy8uBujZatjNMsGA
Hiroshi Fujiwara (BroadBand Tower, Inc.)
Think about a zero trust from information security 10 size menace 2020 (Japanese)
[ Abstract ]
In this talk, we think about a zero trust from information security 10 size menace 2020.
[ Reference URL ]In this talk, we think about a zero trust from information security 10 size menace 2020.
https://forms.gle/Uhy8uBujZatjNMsGA
2020/10/20
Tuesday Seminar on Topology
17:00-18:00 Online
Pre-registration required. See our seminar webpage.
Alexandru Oancea (Sorbonne Université)
Poincaré duality for free loop spaces (ENGLISH)
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
Pre-registration required. See our seminar webpage.
Alexandru Oancea (Sorbonne Université)
Poincaré duality for free loop spaces (ENGLISH)
[ Abstract ]
A certain number of dualities between homological and cohomological invariants of free loop spaces have been observed over the years, having the flavour of Poincaré duality but nevertheless holding in an infinite dimensional setting. The goal of the talk will be to explain these through a new duality theorem, whose proof uses symplectic methods. The talk will report on joint work with Kai Cieliebak and Nancy Hingston.
[ Reference URL ]A certain number of dualities between homological and cohomological invariants of free loop spaces have been observed over the years, having the flavour of Poincaré duality but nevertheless holding in an infinite dimensional setting. The goal of the talk will be to explain these through a new duality theorem, whose proof uses symplectic methods. The talk will report on joint work with Kai Cieliebak and Nancy Hingston.
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
2020/10/19
Seminar on Geometric Complex Analysis
10:30-12:00 Online
MATSUMURA, Shin-ichi (Tohoku University)
On projective manifolds with pseudo-effective tangent bundle
https://zoom.us/meeting/register/tJ0vcu2rrDIqG9Rv5AT0Mpi37urIkJ1IRldB
MATSUMURA, Shin-ichi (Tohoku University)
On projective manifolds with pseudo-effective tangent bundle
[ Abstract ]
In this talk, I would like to discuss projective manifolds whose tangent bundle is pseudo-effective or admits a positively curved singular metric. I will explain a structure theorem for such manifolds and the classification in the two-dimensional case, comparing our theory with classical results for nef tangent bundle or non-negative bisectional curvature. Related open problems will be discussed if time permits.
This is joint work with Genki Hosono (Tohoku University) and Masataka Iwai (Osaka City University).
[ Reference URL ]In this talk, I would like to discuss projective manifolds whose tangent bundle is pseudo-effective or admits a positively curved singular metric. I will explain a structure theorem for such manifolds and the classification in the two-dimensional case, comparing our theory with classical results for nef tangent bundle or non-negative bisectional curvature. Related open problems will be discussed if time permits.
This is joint work with Genki Hosono (Tohoku University) and Masataka Iwai (Osaka City University).
https://zoom.us/meeting/register/tJ0vcu2rrDIqG9Rv5AT0Mpi37urIkJ1IRldB
Seminar on Probability and Statistics
10:30-11:30 Room #Zoom (Graduate School of Math. Sci. Bldg.)
Yuta Koike (University of Tokyo)
Development of high-dimensional CLTs arising from high-frequency data analysis (日本語)
[ Reference URL ]
https://docs.google.com/forms/d/e/1FAIpQLSfDhlzlC6haR8dsDn9_mCxi1s9RtXZxTi_U7Nb_Xl6q7Gw1dA/viewform
Yuta Koike (University of Tokyo)
Development of high-dimensional CLTs arising from high-frequency data analysis (日本語)
[ Reference URL ]
https://docs.google.com/forms/d/e/1FAIpQLSfDhlzlC6haR8dsDn9_mCxi1s9RtXZxTi_U7Nb_Xl6q7Gw1dA/viewform
2020/10/15
Operator Algebra Seminars
16:45-18:15 Online
Sven Raum (Stockholm Univ.)
Structure of Hecke von Neumann algebras and applications to representation theory
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Sven Raum (Stockholm Univ.)
Structure of Hecke von Neumann algebras and applications to representation theory
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Information Mathematics Seminar
16:50-18:35 Room #オンライン(Zoom) (Graduate School of Math. Sci. Bldg.)
Hiroshi Fujiwara (BroadBand Tower, Inc.)
Basics of the speedup technique of the classic computing and Innovation of Causality in the root of the quantum computing (Japanese)
https://forms.gle/Uhy8uBujZatjNMsGA
Hiroshi Fujiwara (BroadBand Tower, Inc.)
Basics of the speedup technique of the classic computing and Innovation of Causality in the root of the quantum computing (Japanese)
[ Abstract ]
Explanation on the speedup technique of the classic computing and Innovation of causality in the root of the quantum computing
[ Reference URL ]Explanation on the speedup technique of the classic computing and Innovation of causality in the root of the quantum computing
https://forms.gle/Uhy8uBujZatjNMsGA
2020/10/12
Seminar on Geometric Complex Analysis
10:30-12:00 Online
NOGUCHI Junjiro (University of Tokyo)
Two topics on psedoconvex domains (Japanese)
[ Reference URL ]
https://zoom.us/meeting/register/tJ0vcu2rrDIqG9Rv5AT0Mpi37urIkJ1IRldB
NOGUCHI Junjiro (University of Tokyo)
Two topics on psedoconvex domains (Japanese)
[ Reference URL ]
https://zoom.us/meeting/register/tJ0vcu2rrDIqG9Rv5AT0Mpi37urIkJ1IRldB
2020/10/08
Operator Algebra Seminars
16:45-18:15 Online
Narutaka Ozawa (RIMS, Kyoto Univ.)
An entropic proof of cutoff on Ramanujan graphs
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Narutaka Ozawa (RIMS, Kyoto Univ.)
An entropic proof of cutoff on Ramanujan graphs
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Information Mathematics Seminar
16:50-18:35 Online
Hiroshi Fujiwara (BroadBand Tower, Inc.)
From a neural network to deep learning (Japanese)
https://forms.gle/Uhy8uBujZatjNMsGA
Hiroshi Fujiwara (BroadBand Tower, Inc.)
From a neural network to deep learning (Japanese)
[ Abstract ]
Explanation on how to reach from a neural network to deep learning
[ Reference URL ]Explanation on how to reach from a neural network to deep learning
https://forms.gle/Uhy8uBujZatjNMsGA
Applied Analysis
16:00-17:30 Room #オンライン開催 (Graduate School of Math. Sci. Bldg.)
( )
(Japanese)
[ Reference URL ]
https://docs.google.com/forms/d/e/1FAIpQLSd7MT077191TeM4aQzeo2hK9Bqn6HQudr3pjLRdmEqND2heqQ/viewform?usp=sf_link
( )
(Japanese)
[ Reference URL ]
https://docs.google.com/forms/d/e/1FAIpQLSd7MT077191TeM4aQzeo2hK9Bqn6HQudr3pjLRdmEqND2heqQ/viewform?usp=sf_link
2020/10/07
Mathematical Biology Seminar
16:00-17:00 Room # (Graduate School of Math. Sci. Bldg.)
Masao Namiki (Former Executive Vice President, Board of Directors and Representative Executive Officers)
The method of the third wave prediction of the infection by the Effective SIQR model (日本語)
Masao Namiki (Former Executive Vice President, Board of Directors and Representative Executive Officers)
The method of the third wave prediction of the infection by the Effective SIQR model (日本語)
2020/10/06
Tuesday Seminar on Topology
17:30-18:30 Online
Pre-registration required. See our seminar webpage.
Shinichiroh Matsuo (Nagoya University)
The Atiyah-Patodi-Singer index of manifolds with boundary and domain-wall fermions (JAPANESE)
https://zoom.us/meeting/register/tJcqdO6pqz0pGNbwpZOpG-o2h4xJwmpma3zL
Pre-registration required. See our seminar webpage.
Shinichiroh Matsuo (Nagoya University)
The Atiyah-Patodi-Singer index of manifolds with boundary and domain-wall fermions (JAPANESE)
[ Abstract ]
We introduce a mathematician-friendly formulation of the physicist-friendly derivation of the Atiyah-Patodi-Singer index.
In a previous work, motivated by the study of lattice gauge theory, we derived a formula expressing the Atiyah-Patodi-Singer index in terms of the eta invariant of “domain-wall fermion Dirac operators” when the base manifold is a flat 4-dimensional torus. Now we generalise this formula to any even dimensional closed Riemannian manifolds, and prove it mathematically rigorously. Our proof uses a Witten localisation argument combined with a devised embedding into a cylinder of one dimension higher. Our viewpoint sheds some new light on the interplay among the Atiyah-Patodi-Singer boundary condition, domain-wall fermions, and edge modes.
This talk is based on a joint paper arXiv:1910.01987, to appear in CMP, with H. Fukaya, M. Furuta, T. Onogi, S. Yamaguchi, and M. Yamashita.
[ Reference URL ]We introduce a mathematician-friendly formulation of the physicist-friendly derivation of the Atiyah-Patodi-Singer index.
In a previous work, motivated by the study of lattice gauge theory, we derived a formula expressing the Atiyah-Patodi-Singer index in terms of the eta invariant of “domain-wall fermion Dirac operators” when the base manifold is a flat 4-dimensional torus. Now we generalise this formula to any even dimensional closed Riemannian manifolds, and prove it mathematically rigorously. Our proof uses a Witten localisation argument combined with a devised embedding into a cylinder of one dimension higher. Our viewpoint sheds some new light on the interplay among the Atiyah-Patodi-Singer boundary condition, domain-wall fermions, and edge modes.
This talk is based on a joint paper arXiv:1910.01987, to appear in CMP, with H. Fukaya, M. Furuta, T. Onogi, S. Yamaguchi, and M. Yamashita.
https://zoom.us/meeting/register/tJcqdO6pqz0pGNbwpZOpG-o2h4xJwmpma3zL
2020/10/01
Information Mathematics Seminar
16:50-18:35 Online
Hiroshi Fujiwara (BroadBand Tower, Inc.)
From the Cyber Attack by the malware to the Zero Trust Network (Japanese)
https://forms.gle/Uhy8uBujZatjNMsGA
Hiroshi Fujiwara (BroadBand Tower, Inc.)
From the Cyber Attack by the malware to the Zero Trust Network (Japanese)
[ Abstract ]
I explain the Cyber Attack by the malware and the Zero Trust Network.
[ Reference URL ]I explain the Cyber Attack by the malware and the Zero Trust Network.
https://forms.gle/Uhy8uBujZatjNMsGA
Operator Algebra Seminars
16:45-18:15 Online
Norio Nawata (Osaka Univ.)
A characterization of the Razak-Jacelon algebra
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Norio Nawata (Osaka Univ.)
A characterization of the Razak-Jacelon algebra
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
2020/09/29
Tuesday Seminar on Topology
17:00-18:00 Online
Pre-registration required. See our seminar webpage.
Kohei Iwaki (The University of Tokyo)
Witten-Reshetikhin-Turaev function for a knot in Seifert manifolds (JAPANESE)
https://zoom.us/meeting/register/tJcqdO6pqz0pGNbwpZOpG-o2h4xJwmpma3zL
Pre-registration required. See our seminar webpage.
Kohei Iwaki (The University of Tokyo)
Witten-Reshetikhin-Turaev function for a knot in Seifert manifolds (JAPANESE)
[ Abstract ]
In 1998, Lawrence-Zagier introduced a certain q-series and proved that its limit value at root of unity q=exp(2π i / K) coincides with the SU(2) Witten-Reshetikhin-Turaev (WRT) invariant of the Poincare homology sphere Σ(2,3,5) at the level K. Employing the idea of Gukov-Marino-Putrov based on resurgent analysis, we generalize the result of Lawrence-Zagier for the Seifert loops (Seifert manifolds with a single loop inside). That is, for each Seifert loop, we introduce an explicit q-series (WRT function) and show that its limit value at the root of unity coincides with the WRT invariant of the Seifert loop. We will also discuss a q-difference equation satisfied by the WRT function. This talk is based on a joint work with H. Fuji, H. Murakami and Y. Terashima which is available on arXiv:2007.15872.
[ Reference URL ]In 1998, Lawrence-Zagier introduced a certain q-series and proved that its limit value at root of unity q=exp(2π i / K) coincides with the SU(2) Witten-Reshetikhin-Turaev (WRT) invariant of the Poincare homology sphere Σ(2,3,5) at the level K. Employing the idea of Gukov-Marino-Putrov based on resurgent analysis, we generalize the result of Lawrence-Zagier for the Seifert loops (Seifert manifolds with a single loop inside). That is, for each Seifert loop, we introduce an explicit q-series (WRT function) and show that its limit value at the root of unity coincides with the WRT invariant of the Seifert loop. We will also discuss a q-difference equation satisfied by the WRT function. This talk is based on a joint work with H. Fuji, H. Murakami and Y. Terashima which is available on arXiv:2007.15872.
https://zoom.us/meeting/register/tJcqdO6pqz0pGNbwpZOpG-o2h4xJwmpma3zL
2020/08/26
thesis presentations
16:00-17:15 Online
ITO Yohei (Graduate Scool of Mathematical Sciences University of tokyo)
Irregular Riemann–Hilbert correspondence and its applications to Fourier transforms of holonomic D-modules
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
ITO Yohei (Graduate Scool of Mathematical Sciences University of tokyo)
Irregular Riemann–Hilbert correspondence and its applications to Fourier transforms of holonomic D-modules
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
2020/07/31
thesis presentations
10:30-11:45 Online
INOUE Eiji (Graduate Scool of Mathematical Sciences University of tokyo)
Theory on Kähler metrics with constant exponentially weighted scalar curvature and exponentially weighted K-stability including Kähler-Ricci solitons
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
INOUE Eiji (Graduate Scool of Mathematical Sciences University of tokyo)
Theory on Kähler metrics with constant exponentially weighted scalar curvature and exponentially weighted K-stability including Kähler-Ricci solitons
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
thesis presentations
13:15-14:30 Online
INAYAMA Takahiro (Graduate Scool of Mathematical Sciences University of tokyo)
Studies on singular Hermitian metrics on holomorphic vector bundles via L² estimates and L² extension theorems
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
INAYAMA Takahiro (Graduate Scool of Mathematical Sciences University of tokyo)
Studies on singular Hermitian metrics on holomorphic vector bundles via L² estimates and L² extension theorems
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
2020/07/30
thesis presentations
10:30-11:45 Online
LIN Dexie (Graduate Scool of Mathematical Sciences University of tokyo)
Monopole Floer homology for codimension-3 Riemannian foliation
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
LIN Dexie (Graduate Scool of Mathematical Sciences University of tokyo)
Monopole Floer homology for codimension-3 Riemannian foliation
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
2020/07/28
Tuesday Seminar on Topology
17:00-18:00 Online
Pre-registration required. See our seminar webpage.
Anderson Vera (RIMS, Kyoto University)
A double filtration for the mapping class group and the Goeritz group of the sphere (ENGLISH)
https://zoom.us/webinar/register/WN_oS594Z6BRyaKNCvlm3yCoQ
Pre-registration required. See our seminar webpage.
Anderson Vera (RIMS, Kyoto University)
A double filtration for the mapping class group and the Goeritz group of the sphere (ENGLISH)
[ Abstract ]
I will talk about a double-indexed filtration of the mapping class group and of the Goeritz group of the sphere, the latter is the group of isotopy classes of self-homeomorphisms of the 3-sphere which preserves the standard Heegaard splitting of $S^3$. In particular I will explain how this double filtration allows to write the Torelli group as a product of some subgroups of the mapping class group. A similar study could be done for the group of automorphisms of a free group. (work in progress with K. Habiro)
[ Reference URL ]I will talk about a double-indexed filtration of the mapping class group and of the Goeritz group of the sphere, the latter is the group of isotopy classes of self-homeomorphisms of the 3-sphere which preserves the standard Heegaard splitting of $S^3$. In particular I will explain how this double filtration allows to write the Torelli group as a product of some subgroups of the mapping class group. A similar study could be done for the group of automorphisms of a free group. (work in progress with K. Habiro)
https://zoom.us/webinar/register/WN_oS594Z6BRyaKNCvlm3yCoQ
thesis presentations
10:30-11:45 Online
Brkin,Sergei Vladimirovich (Graduate Scool of Mathematical Sciences University of tokyo)
Twisted arrow categories of operads and Segal conditions
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
Brkin,Sergei Vladimirovich (Graduate Scool of Mathematical Sciences University of tokyo)
Twisted arrow categories of operads and Segal conditions
[ Reference URL ]
https://forms.gle/jfh9Hpyt3XZXXcft6
2020/07/21
Numerical Analysis Seminar
16:30-18:00 Online
Tomoya Kemmochi (Nagoya University)
Structure-preserving numerical schemes for constrained gradient flows of planar curves (Japanese)
[ Reference URL ]
https://forms.gle/3JiNEjWnrWLW8cFA9
Tomoya Kemmochi (Nagoya University)
Structure-preserving numerical schemes for constrained gradient flows of planar curves (Japanese)
[ Reference URL ]
https://forms.gle/3JiNEjWnrWLW8cFA9
< Previous 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193 Next >
