## Seminar information archive

Seminar information archive ～05/26｜Today's seminar 05/27 | Future seminars 05/28～

#### GCOE Seminars

14:40-15:40 Room #118 (Graduate School of Math. Sci. Bldg.)

Unique Cartan decomposition for II$_1$ factors arising from cross section equivalence relations (ENGLISH)

[ Reference URL ]

http://www.ms.u-tokyo.ac.jp/~yasuyuki/mini2013-2.htm

**Arnaud Brothier**(KU Leuven)Unique Cartan decomposition for II$_1$ factors arising from cross section equivalence relations (ENGLISH)

[ Reference URL ]

http://www.ms.u-tokyo.ac.jp/~yasuyuki/mini2013-2.htm

#### GCOE Seminars

15:55-16:55 Room #118 (Graduate School of Math. Sci. Bldg.)

TBA (ENGLISH)

[ Reference URL ]

http://www.ms.u-tokyo.ac.jp/~yasuyuki/mini2013-2.htm

**Michael Hartglass**(UC Berkeley)TBA (ENGLISH)

[ Reference URL ]

http://www.ms.u-tokyo.ac.jp/~yasuyuki/mini2013-2.htm

#### GCOE Seminars

16:00-17:00 Room #370 (Graduate School of Math. Sci. Bldg.)

3-D Calderon's Problem with partial Dirichlet-to Neumann map (ENGLISH)

**Oleg Emanouilov**(Colorado State University)3-D Calderon's Problem with partial Dirichlet-to Neumann map (ENGLISH)

[ Abstract ]

We present new results for the uniqueness of recovery of a potential in three dimensional Calderon's problem with partial Dirichlet-to-Neumann map.

The proof is based on complex geometric optics solutions and the Radon transform.

We present new results for the uniqueness of recovery of a potential in three dimensional Calderon's problem with partial Dirichlet-to-Neumann map.

The proof is based on complex geometric optics solutions and the Radon transform.

### 2013/01/15

#### Mathematical Biology Seminar

14:00-16:00 Room #152 (Graduate School of Math. Sci. Bldg.)

Bolyai Institute, University of Szeged)

Differential equation models describing cell proliferation process and their dynamics (JAPANESE)

**Yukihiko Nakata**(Bolyai Institute, University of Szeged)

Differential equation models describing cell proliferation process and their dynamics (JAPANESE)

#### Numerical Analysis Seminar

16:30-18:00 Room #002 (Graduate School of Math. Sci. Bldg.)

On the rigorous numerical verification of saddle-saddle connections (JAPANESE)

[ Reference URL ]

http://www.infsup.jp/utnas/

**Kaname Matsue**(Tohoku University)On the rigorous numerical verification of saddle-saddle connections (JAPANESE)

[ Reference URL ]

http://www.infsup.jp/utnas/

#### Mathematical Biology Seminar

14:00-16:00 Room #152 (Graduate School of Math. Sci. Bldg.)

Formulation of transient amplifying cell population growth process based on generation progression models (JAPANESE)

**Shinji Nakaoka**(RIKEN)Formulation of transient amplifying cell population growth process based on generation progression models (JAPANESE)

#### Algebraic Geometry Seminar

15:30-17:00 Room #128 (Graduate School of Math. Sci. Bldg.)

Three Dimensional Birational Geoemtry--updates and problems (ENGLISH)

**Jungkai Alfred Chen**(National Taiwan University)Three Dimensional Birational Geoemtry--updates and problems (ENGLISH)

[ Abstract ]

In this talk I will talk about some recent results on

biratioanl classification and biratioanl geoemtry of threefolds.

Given a threefold of general type, we improved our previous result by

showing that $Vol \\ge 1/1680$ and $|mK_X|$ is biratioanl for $m \\ge

61$.

Compare with the worst known example that $X_{46} \\subset

\\mathbb{P}(4,5,6,7,23)$, one also knows that there are only finiteley

many singularities type

for threefolds of general type with $1/1680 \\le Vol \\le 1/420$. It is

then intereting to study threefolds of general type with given basket

of singularities and with given fiber structure.

Concerning threefolds with intermediate Kodaira dimension, we

considered the effective Iitaka fibration. For this purpose, it is

interesting to study threefolds with $\\kappa=1$ with given basket of

singularities and abelian fibration.

For explicit birational geoemtry, we will show our result that each

biratioanl map in minimal model program can be factored into a

sequence of following maps (or its inverse)

1. a divisorial contraction to a point of index r with discrepancy 1/r.

2. a blowup along a smooth curve

3. a flop

In this talk I will talk about some recent results on

biratioanl classification and biratioanl geoemtry of threefolds.

Given a threefold of general type, we improved our previous result by

showing that $Vol \\ge 1/1680$ and $|mK_X|$ is biratioanl for $m \\ge

61$.

Compare with the worst known example that $X_{46} \\subset

\\mathbb{P}(4,5,6,7,23)$, one also knows that there are only finiteley

many singularities type

for threefolds of general type with $1/1680 \\le Vol \\le 1/420$. It is

then intereting to study threefolds of general type with given basket

of singularities and with given fiber structure.

Concerning threefolds with intermediate Kodaira dimension, we

considered the effective Iitaka fibration. For this purpose, it is

interesting to study threefolds with $\\kappa=1$ with given basket of

singularities and abelian fibration.

For explicit birational geoemtry, we will show our result that each

biratioanl map in minimal model program can be factored into a

sequence of following maps (or its inverse)

1. a divisorial contraction to a point of index r with discrepancy 1/r.

2. a blowup along a smooth curve

3. a flop

### 2013/01/11

#### Lectures

10:00-11:00 Room #123 (Graduate School of Math. Sci. Bldg.)

A duality between easy quantum groups and reflection groups (ENGLISH)

**Sven Raum**(KU Leuven)A duality between easy quantum groups and reflection groups (ENGLISH)

#### Lectures

11:15-12:15 Room #123 (Graduate School of Math. Sci. Bldg.)

Some non-uniqueness results for Cartan subalgebras in II$_1$ factors (ENGLISH)

**An Speelman**(KU Leuven)Some non-uniqueness results for Cartan subalgebras in II$_1$ factors (ENGLISH)

#### Lectures

14:00-15:00 Room #123 (Graduate School of Math. Sci. Bldg.)

Structural results for II$_1$ factors of negatively curved groups (ENGLISH)

**Ionut Chifan**(University of Iowa)Structural results for II$_1$ factors of negatively curved groups (ENGLISH)

#### Lectures

15:15-16:15 Room #123 (Graduate School of Math. Sci. Bldg.)

UHF slicing and classification of nuclear $C^*$-algebras (ENGLISH)

**Karen Strung**(Universit\"at M\"unster)UHF slicing and classification of nuclear $C^*$-algebras (ENGLISH)

#### Lectures

16:30-17:30 Room #123 (Graduate School of Math. Sci. Bldg.)

The generator problem for $C^*$-algebras (ENGLISH)

**Hannes Thiel**(University of Copenhagen)The generator problem for $C^*$-algebras (ENGLISH)

#### GCOE Seminars

10:00-11:00 Room #123 (Graduate School of Math. Sci. Bldg.)

A duality between easy quantum groups and reflection groups (ENGLISH)

[ Reference URL ]

http://www.ms.u-tokyo.ac.jp/~yasuyuki/mini2013-1.htm

**Sven Raum**(KU Leuven)A duality between easy quantum groups and reflection groups (ENGLISH)

[ Reference URL ]

http://www.ms.u-tokyo.ac.jp/~yasuyuki/mini2013-1.htm

#### GCOE Seminars

11:15-12:15 Room #123 (Graduate School of Math. Sci. Bldg.)

Some non-uniqueness results for Cartan subalgebras in II$_1$ factors (ENGLISH)

[ Reference URL ]

http://www.ms.u-tokyo.ac.jp/~yasuyuki/mini2013-1.htm

**An Speelman**(KU Leuven)Some non-uniqueness results for Cartan subalgebras in II$_1$ factors (ENGLISH)

[ Reference URL ]

http://www.ms.u-tokyo.ac.jp/~yasuyuki/mini2013-1.htm

### 2013/01/08

#### Lie Groups and Representation Theory

16:30-18:00 Room #126 (Graduate School of Math. Sci. Bldg.)

On the group of holomorphic and anti-holomorphic transformations

of a compact Hermitian symmetric space and the $G$-structure (JAPANESE)

**Soji Kaneyuki**(Sophia University )On the group of holomorphic and anti-holomorphic transformations

of a compact Hermitian symmetric space and the $G$-structure (JAPANESE)

[ Abstract ]

Let $M$ be a compact irreducible Hermitian symmetric space. We determine the full group of holomorphic and anti-holomorphic transformations of $M$. Also we characterize that full group as the automorphism group of the $G$-structure on $M$, called a generalized conformal structure.

Let $M$ be a compact irreducible Hermitian symmetric space. We determine the full group of holomorphic and anti-holomorphic transformations of $M$. Also we characterize that full group as the automorphism group of the $G$-structure on $M$, called a generalized conformal structure.

#### GCOE lecture series

16:30-17:30 Room #118 (Graduate School of Math. Sci. Bldg.)

Probing factions and Direct sampling method (ENGLISH)

**Kazufumi Ito**(North Carolina State Univ.)Probing factions and Direct sampling method (ENGLISH)

[ Abstract ]

We develop probing functions for inverse medium problems arising in Helmholtz and conductivity and Schrodinger equations. direct sampling methods for determining inhomogeneous inclusions using a limited number of Cauchy data.

We develop probing functions for inverse medium problems arising in Helmholtz and conductivity and Schrodinger equations. direct sampling methods for determining inhomogeneous inclusions using a limited number of Cauchy data.

### 2013/01/07

#### GCOE lecture series

16:30-17:30 Room #118 (Graduate School of Math. Sci. Bldg.)

Traffic flow modeling and Hamilton Jacobi equation (ENGLISH)

**Kazufumi Ito**(North Carolina State Univ.)Traffic flow modeling and Hamilton Jacobi equation (ENGLISH)

[ Abstract ]

A traffic model based on Hamilton Jacobi equations are developed. The model incorporates the sag and source conditions of traffic flows and predict and classify the traffic congestion.

A traffic model based on Hamilton Jacobi equations are developed. The model incorporates the sag and source conditions of traffic flows and predict and classify the traffic congestion.

### 2012/12/26

#### Operator Algebra Seminars

15:45-18:00 Room #118 (Graduate School of Math. Sci. Bldg.)

Trouble in paradise (ENGLISH)

Algebraic K-theory of generalized schemes (ENGLISH)

**Henrik Densing Petersen**(Univ. Copenhagen) 15:45-16:45Trouble in paradise (ENGLISH)

**Stella Anevski**(Univ. Copenhagen) 17:00-18:00Algebraic K-theory of generalized schemes (ENGLISH)

### 2012/12/21

#### GCOE lecture series

15:00-16:00 Room #126 (Graduate School of Math. Sci. Bldg.)

Evolution equation approach to Fractional Differential Equations (ENGLISH)

**Kazufumi Ito**(North Carolina State Univ.)Evolution equation approach to Fractional Differential Equations (ENGLISH)

[ Abstract ]

A class of fractional differential equations is formulated as an evolution equation on the memory space with non-local boundary condition. Based on such a formulation the mathematical theory of evolution equations is applied to concrete examples of nonlinear fractional PDEs.

A class of fractional differential equations is formulated as an evolution equation on the memory space with non-local boundary condition. Based on such a formulation the mathematical theory of evolution equations is applied to concrete examples of nonlinear fractional PDEs.

### 2012/12/19

#### Operator Algebra Seminars

15:45-18:00 Room #118 (Graduate School of Math. Sci. Bldg.)

$W^*$-superrigidity for left-right wreath products (ENGLISH)

A classification of approximate subhomogeneous $C^*$-algebras (ENGLISH)

**Mihaita Berbec**(KU Leuven) 15:45-16:45$W^*$-superrigidity for left-right wreath products (ENGLISH)

**Zhuang Niu**(Univ. Wyoming) 17:00-18:00A classification of approximate subhomogeneous $C^*$-algebras (ENGLISH)

#### Geometry Colloquium

10:30-12:00 Room #128 (Graduate School of Math. Sci. Bldg.)

Funk metric on Weil-Petersson spaces (JAPANESE)

**FUJIWARA, Koji**(Kyoto University)Funk metric on Weil-Petersson spaces (JAPANESE)

[ Abstract ]

We discuss the Funk function $F(x; y)$ on a Teichmuller space with the Weil-Petersson metric introduced by Yamada, $F(x; y)$ is an asymmetric distance and invariant by the action of the mapping class group. The Funk metric was originally studied for an open convex subset in a Euclidean space by Funk. Its symmetrization is the Hilbert metric.

We discuss the Funk function $F(x; y)$ on a Teichmuller space with the Weil-Petersson metric introduced by Yamada, $F(x; y)$ is an asymmetric distance and invariant by the action of the mapping class group. The Funk metric was originally studied for an open convex subset in a Euclidean space by Funk. Its symmetrization is the Hilbert metric.

#### Number Theory Seminar

16:40-17:40 Room #056 (Graduate School of Math. Sci. Bldg.)

A generalization of Kato's local epsilon conjecture for

(φ, Γ)-modules over the Robba ring (JAPANESE)

**Kentarou Nakamura**(Hokkaido University)A generalization of Kato's local epsilon conjecture for

(φ, Γ)-modules over the Robba ring (JAPANESE)

[ Abstract ]

In his preprint “Lectures on the approach to Iwasawa theory of Hasse-Weil L-functions via B_dR, Part II ", Kazuya Kato proposed a conjecture called local epsilon conjecture. This conjecture predicts that the determinant of the Galois cohomology of a family of p-adic Galois representations has a canonical base whose specializations at de Rham points can be characterized by using Bloch-Kato exponential, L-factors and Deligne-Langlands epsilon constants of the associated Weil-Deligne representations.

In my talk, I generalize his conjecture for families of (φ, Γ)-modules over the Robba ring, and prove a part of this conjecture in the trianguline case. The two key ingredients are the recent result of Kedlaya-Pottharst-Xiao on the ﬁniteness of cohomologies of (φ, Γ)-modules and my result on Bloch-Kato exponential map for (φ, Γ)-modules.

In his preprint “Lectures on the approach to Iwasawa theory of Hasse-Weil L-functions via B_dR, Part II ", Kazuya Kato proposed a conjecture called local epsilon conjecture. This conjecture predicts that the determinant of the Galois cohomology of a family of p-adic Galois representations has a canonical base whose specializations at de Rham points can be characterized by using Bloch-Kato exponential, L-factors and Deligne-Langlands epsilon constants of the associated Weil-Deligne representations.

In my talk, I generalize his conjecture for families of (φ, Γ)-modules over the Robba ring, and prove a part of this conjecture in the trianguline case. The two key ingredients are the recent result of Kedlaya-Pottharst-Xiao on the ﬁniteness of cohomologies of (φ, Γ)-modules and my result on Bloch-Kato exponential map for (φ, Γ)-modules.

#### GCOE Seminars

15:45-16:45 Room #118 (Graduate School of Math. Sci. Bldg.)

$W^*$-superrigidity for left-right wreath products (ENGLISH)

**Mihaita Berbec**(KU Leuven)$W^*$-superrigidity for left-right wreath products (ENGLISH)

### 2012/12/18

#### FMSP Lectures

10:30-11:30 Room #056 (Graduate School of Math. Sci. Bldg.)

On convergence to equilibrium with applications of Lojasiewicz-Simon

inequality (II) (ENGLISH)

**Jie Jiang**(Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences)On convergence to equilibrium with applications of Lojasiewicz-Simon

inequality (II) (ENGLISH)

### 2012/12/17

#### Seminar on Geometric Complex Analysis

10:30-12:00 Room #126 (Graduate School of Math. Sci. Bldg.)

On the existence of strictly effective basis on an arithmetic variety (JAPANESE)

**Hideaki Ikoma**(Kyoto University)On the existence of strictly effective basis on an arithmetic variety (JAPANESE)

[ Abstract ]

I would like to talk about some recent work of mine on the asymptotic behavior of the successive minima associated to a graded arithmetic linear series. A complete arithmetic linear series belonging to a hermitian line bundle on an arithmetic variety is defined as the Z-module of the global sections endowed with the supremum-norm, and the successive minima are invariants that measure the size of the sections with small norms.

If time permits, I would like to also explain some close relationship between the results and the general equi-distribution theory of rational points on an arithmetic variety.

I would like to talk about some recent work of mine on the asymptotic behavior of the successive minima associated to a graded arithmetic linear series. A complete arithmetic linear series belonging to a hermitian line bundle on an arithmetic variety is defined as the Z-module of the global sections endowed with the supremum-norm, and the successive minima are invariants that measure the size of the sections with small norms.

If time permits, I would like to also explain some close relationship between the results and the general equi-distribution theory of rational points on an arithmetic variety.

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