## 過去の記録

### 2013年10月08日(火)

#### トポロジー火曜セミナー

16:30-18:00   数理科学研究科棟(駒場) 056号室
Tea: 16:00 - 16:30 コモンルーム

An invariant of rational homology 3-spheres via vector fields. (JAPANESE)
[ 講演概要 ]
In this talk, we define an invariant of rational homology 3-spheres with
values in a space $\\mathcal A(\\emptyset)$ of Jacobi diagrams by using
vector fields.
The construction of our invariant is a generalization of both that of
the Kontsevich-Kuperberg-Thurston invariant $z^{KKT}$
and that of Fukaya and Watanabe's Morse homotopy invariant $z^{FW}$.
As an application of our invariant, we prove that $z^{KKT}=z^{FW}$ for
integral homology 3-spheres.

### 2013年10月07日(月)

#### 複素解析幾何セミナー

10:30-12:00   数理科学研究科棟(駒場) 126号室

The limits on boundary of orbifold Kähler-Einstein metrics and orbifold Kähler-Ricci flows over quasi-projective manifolds (JAPANESE)
[ 講演概要 ]
In this talk, we consider a sequence of orbifold Kähler-Einstein metrics of negative Ricci curvature or corresponding orbifold normalized Kähler-Ricci flows on a quasi-projective manifold with ample log-canonical bundle for a simple normal crossing divisor. Tian-Yau, S. Bando and H. Tsuji established that the sequence of orbifold Kähler-Einstein metrics converged to the complete Käler-Einstein metric of negative Ricci curvature on the complement of the boundary divisor. The main purpose of this talk is to show that such a convergence is also true on the boundary for both of the orbifold Kähler-Einstein metrics and the orbifold normalized Kähler-Ricci flows.

### 2013年10月03日(木)

#### 幾何コロキウム

10:00-11:30   数理科学研究科棟(駒場) 122号室

A rigidity lemma for cocycles over BS(1,k)-actions (JAPANESE)
[ 講演概要 ]

### 2013年10月02日(水)

#### 作用素環セミナー

16:30-18:00   数理科学研究科棟(駒場) 118号室

A classification of flows on AFD factors with faithful Connes-Takesaki modules
(JAPANESE)

### 2013年10月01日(火)

#### トポロジー火曜セミナー

16:30-18:00   数理科学研究科棟(駒場) 056号室
Tea: 16:00 - 16:30 コモンルーム

The geography problem of Lefschetz fibrations (JAPANESE)
[ 講演概要 ]
To consider holomorphic fibrations complex surfaces over complex curves
and Lefschetz fibrations over surfaces is one method for the study of
complex surfaces of general type and symplectic 4-manifods, respectively.
In this talk, by comparing the geography problem of relatively minimal
holomorphic fibrations with that of relatively minimal Lefschetz
fibrations (i.e., the characterization of pairs $(x,y)$ of certain
invariants $x$ and $y$ corresponding to relatively minimal holomorphic
fibrations and relatively minimal Lefschetz fibrations), we observe the
difference between complex surfaces of general type and symplectic
4-manifolds. In particular, we construct Lefschetz fibrations violating
the slope inequality" which holds for any relatively minimal holomorphic
fibrations.

### 2013年09月10日(火)

#### 保型形式の整数論月例セミナー

13:30-15:00   数理科学研究科棟(駒場) 123号室
Yuval Flicker 氏 (Ohio State Univ. ) 13:30-15:00
Counting automorphic representations (JAPANESE)
Yuval Flicker 氏 (Ohio State Univeristy) 13:30-15:00
Counting automorphic representations II (JAPANESE)

### 2013年09月07日(土)

#### FMSPレクチャーズ

15:00-16:30   数理科学研究科棟(駒場) 123号室
Bertrand Deroin 氏 (University of Paris-Sud)
Dominating representations by Fuchsian ones (ENGLISH)
[ 講演概要 ]
We will focus on the problem of dominating the translation lengths of a representation from a surface group to the isometries of a CAT(-1) space by the lengths induced by a hyperbolic structure on the surface. This is related to the construction of 3-dimensional anti-de-Sitter compact manifolds. This is a collaboration with Nicolas Tholozan.

### 2013年08月12日(月)

#### 作用素環セミナー

16:30-18:00   数理科学研究科棟(駒場) 118号室
Roberto Longo 氏 (Univ. Roma, Tor Vergata)
Operator Algebraic Construction of Quantum Field Theory Models (ENGLISH)

#### FMSPレクチャーズ

16:30-18:00   数理科学研究科棟(駒場) 118号室
Roberto Longo 氏 (Univ. Roma, Tor Vergata)
Operator Algebraic Construction of Quantum Field Theory Models (ENGLISH)

### 2013年08月09日(金)

#### 作用素環セミナー

16:30-18:00   数理科学研究科棟(駒場) 118号室
Tullio Ceccherini-Silberstein 氏 (Univ. Sannio)
Cellular automata and groups (ENGLISH)

### 2013年08月08日(木)

#### 作用素環セミナー

16:30-18:00   数理科学研究科棟(駒場) 118号室
Demosthenes Ellinas 氏 (Technical University of Crete)
Phase Plane Operator Valued Probability Measures: Constructions and Random Evolution (ENGLISH)

### 2013年08月07日(水)

#### FMSPレクチャーズ

16:00-17:00   数理科学研究科棟(駒場) 370号室
Philippe Guyenne 氏 (Univ. of Delaware)
Water waves over a random bottom (ENGLISH)
[ 講演概要 ]
We present a Hamiltonian formulation for nonlinear surface water waves in the presence of a variable bottom. This formulation is based on a reduction of the problem to a lower-dimensional system involving boundary variables alone. To accomplish this, we express the Dirichlet-to-Neumann operator as a Taylor series in terms of the surface and bottom variations. This expansion is convenient for both asymptotic calculations and numerical simulations. First we apply this formulation to the asymptotic description of long waves over random topography. We show that the principal component of the solution can be described by a Korteweg-de Vries equation plus random phase corrections. We also derive an asymptotic expression for the scattered component. Finally numerical simulations will be shown to illustrate the theoretical results. This is joint work with Walter Craig and Catherine Sulem.

### 2013年07月29日(月)

#### 数理人口学・数理生物学セミナー

16:30-18:00   数理科学研究科棟(駒場) 118号室

[ 講演概要 ]

ペストやマラリアなどの媒介生物による感染症の伝播を調べるために,

する近年の応用例および結果も様々に紹介したい.

### 2013年07月26日(金)

#### 博士論文発表会

13:00-14:15   数理科学研究科棟(駒場) 122号室

Examples of factors which have no Cartan subalgebras(カルタン部分環を持たない因子環の例) (JAPANESE)

#### FMSPレクチャーズ

10:30-12:00   数理科学研究科棟(駒場) 118号室
Birgit Speh 氏 (Cornell University)
Representations of reductive groups and L-functions (II) (ENGLISH)
[ 講演概要 ]
In the second lecture we will quickly discuss Rankin Selberg integral approach to L-factors and then Shahidi's method of constructing L-functions by relating them to intertwining operators, leading to the definition of the the L-factors of tempered non degenerate representations. The lecture closes with a discussion of L-factors for nontempered representations.

#### 談話会・数理科学講演会

16:30-17:30   数理科学研究科棟(駒場) 123号室

お茶&Coffee&お菓子: 16:00～16:30 (コモンルーム)。

Matthias Hieber 氏 (TU Darmstadt, Germany)
Analysis of the Navier-Stokes and Complex Fluids Flow (ENGLISH)
[ 講演概要 ]
In this talk, we discuss the dynamics of fluid flow generated by the Navier-Stokes equations or, more generally, by models describing complex fluid flows. Besides classical questions concerning well-posedness of the underlying equations, we investigate analytically models arising in the theory of free boundary value problems, viscoelastic fluids and liquid crystals.

### 2013年07月25日(木)

#### 博士論文発表会

15:00-16:15   数理科学研究科棟(駒場) 122号室

Discrete integrable equations over finite fields(有限体上の離散可積分方程式) (JAPANESE)

#### 講演会

13:00-15:00   数理科学研究科棟(駒場) 126号室
Joergen E Andersen 氏 (Centre for Quantum Geometry of Moduli Spaces (QGM), Aarhus University, Denmark
)
モジュライ構造とChern-Simons量子場理論 (ENGLISH)

### 2013年07月24日(水)

#### 代数学コロキウム

16:40-17:40   数理科学研究科棟(駒場) 056号室

The determinant of a double covering of the projective space of even dimension and the discriminant of the branch locus (JAPANESE)

#### 作用素環セミナー

16:30-18:00   数理科学研究科棟(駒場) 118号室
Mikael Pichot 氏 (McGill Univ.)
The sofic property for groups and dynamical systems (ENGLISH)

### 2013年07月23日(火)

#### PDE実解析研究会

10:30-11:30   数理科学研究科棟(駒場) 056号室

Matthias Hieber 氏 (Technische Universität Darmstadt)
Analysis of the Simplified Ericksen-Leslie Model for Liquid Crystals (ENGLISH)
[ 講演概要 ]
Consider the Ericksen-Leslie model for the flow of liquid crystals in a bounded domain $\\Omega \\subset \\R^n$. In this talk we discuss various simplifications of the general model and describe a dynamic theory for the simplified equations by analyzing it as a quasilinear system. In particular, we show the existence of a unique, global, strong solutions to this system provided the initial data are close to an equilibrium or the solution is eventually bounded in the norm of the underlying state space. In this case the solution converges exponentially to an equilibrium. Moreover, the solution is shown to be real analytic, jointly in time and space.
We further analyze a non-isothermal extension of this model safisfying the first and second law of thermodynamics and show that results of the above type hold as well in this setting.
This is joint work with M. Nesensohn, J. Prüss and K. Schade.

#### 数値解析セミナー

16:30-18:00   数理科学研究科棟(駒場) 002号室

[ 講演概要 ]

[ 講演参考URL ]
http://www.infsup.jp/utnas/

#### 講演会

13:00-15:00   数理科学研究科棟(駒場) 002号室
Joergen E Andersen 氏 (Centre for Quantum Geometry of Moduli Spaces (QGM), Aarhus University, Denmark
)
モジュライ構造と蛋白質構造のクラスタリング (ENGLISH)

### 2013年07月22日(月)

#### 博士論文発表会

13:30-14:45   数理科学研究科棟(駒場) 128号室

The Stokes semigroup on non-decaying spaces（非減衰空間上のストークス半群） (JAPANESE)

#### 博士論文発表会

15:30-16:45   数理科学研究科棟(駒場) 128号室

A few topics related to maximum principles（最大値原理に関連する諸課題） (JAPANESE)