| (Chair: Tetsuya Shiromizu) | ||
| 19:00 -- 20:30 | Takahiko Matsubara | The Lagrangian resummation theory |
| Abstract: The large-scale structure (LSS) of the universe has attracted renewed interests these days, as a probe of such as the dark energy, primordial non-Gaussianity, and modified gravity, etc. Many ambitious plans of galaxy redshift survey have been proposed, including BigBOSS, HETDEX, LAMOST, SKA, SuMIRe, Eulid, WFIRST, etc. Understanding precise properties of dynamics in LSS is crucial to extract cosmological information from those huge redshift surveys. We have developed a new approach to the nonlinear perturbation theory, which is called the Lagrangian resummation theory (LRT), to predict the observable power spectrum and polyspectra. The biasing and redshift-space distortions are naturally incorporated in this approach. Once a model of galaxy biasing is given, no free parameter is present in this theory. | ||
| (Chair: Jun'ichi Yokoyama) | ||
| 09:30 -- 10:30 | Takeshi Chiba | Constancy of the Constants of Nature: Update |
| 11:00 -- 12:00 | Tsutomu Kobayashi | Galileon Cosmology I |
(Chair: M. Yamaguchi) | ||
| 14:00 -- 15:00 | Tsutomu Kobayashi | Galileon Cosmology II |
(Chair: Bernard Carr) | ||
| 15:15 -- 15:45 | Shuntaro Mizuno | Primordial non-Gaussianity from the multi-field DBI Galileon [ppt] |
| Abstract: We study an extension of multi-field DBI inflation models by adding an induced gravity term on a probe D3 brane. The induced gravity term gives rise to the quartic Galileon term when the motion of the brane is non-relativistic. We derive equations of motion on a general background and study conditions to realise inflation. In the relativistic limit, large non-Gaussianity of primordial curvature perturbation is generated during inflation as in DBI inflation models. Depending on a choice of parameters, there arises the orthogonal shape of the bispectrum. | ||
| 16:00 -- 16:30 | Shinji Tsujikawa | Inflation in modified gravitational theories [ppt] |
| Abstract: We study chaotic inflation in the context of modified gravitational theories. Our analysis covers models based on (i) a field coupling $\omega(\phi)$ with the kinetic energy $X$ and a nonmimimal coupling $\zeta \phi^{2} R/2$ with a Ricci scalar $R$, (ii) Brans-Dicke (BD) theories, (iii) Gauss-Bonnet (GB) gravity, and (iv) gravity with a Galileon correction. Dilatonic coupling with the kinetic energy and/or negative nonminimal coupling are shown to lead to compatibility with observations of the Cosmic Microwave Background (CMB) temperature anisotropies for the self-coupling inflaton potential $V(\phi)=\lambda \phi^{4}/4$. BD theory with a quadratic inflaton potential, which covers Starobinsky's $f(R)$ model $f(R)=R+R^{2}/(6M^{2})$ with the BD parameter $\omega_{BD}=0$, gives rise to a smaller tensor-to-scalar ratio for decreasing $\omega_{BD}$. In the presence of a GB term coupled to the field $\phi$, we express the scalar/tensor spectral indices $n_{s}$ and $n_{t}$ as well as the tensor-to-scalar ratio $r$ in terms of two slow-roll parameters and place bounds on the strength of the GB coupling from the joint data analysis of WMAP 7yr combined with other observations. We also study the Galileon-like self-interaction $\Phi(\phi) X \square\phi$ with exponential coupling $\Phi(\phi) \propto e^{\mu\phi}$. Using a CMB likelihood analysis we put bounds on the strength of the Galileon coupling and show that the self coupling potential can in fact be made compatible with observations in the presence of the exponential coupling with $\mu>0$. [References] 1. A. De Felice, S. Tsujikawa, J. Elliston and R. Tavakol, ``Chaotic inflation in modified gravitational theories,'' arXiv:1105.4685 [astro-ph.CO]. 2. A.~De Felice and S.~Tsujikawa, ``Primordial non-Gaussianities in general modified gravitational models of inflation,'' JCAP 1104, 029 (2011) | ||
| 16:40 -- 17:10 | Antonio De Felice | Stability of spherical symmetric spacetimesin Modified Gravity |
| Abstract: We show here the study of stability of spherically symmetric spacetimes in Modified Gravity models in the form of f(R,G) where R is the Ricci scalar and G is the Gauss-Bonnet term. | ||
| (Chair: Jiro Soda) | ||
| 09:30 -- 10:30 | Takeshi Kobayashi | Aspects of D-Brane Inflation in String Cosmology |
| Abstract: Inflationary cosmology in the framework of string theory will be discussed, with special emphasis on D-brane inflation models. I will explain three domains of D-brane inflation: slow-rolling, rapid-rolling, and relativistically moving D-branes. It will be shown that the slow-roll and relativistic limits of D-brane inflation suffer from a large mass related to moduli stabilization, and from geometrical constraints on the inflaton field range, respectively. In particular I will argue that the intermediate domain, namely, rapid-rolling D-branes can circumvent such problems and support a sufficiently long inflationary era. Furthermore, since rapid-rolling inflatons do not produce scale-invariant primordial perturbations, I will present a curvaton model from D-branes located in a warped throat region of the internal space. | ||
(Chair: Takahiro Tanaka) | ||
| 11:00 -- 12:00 | Yasuhiro Sekino | Topics in eternal inflation [ppt] |
| Abstract: There is evidence that string theory has many de Sitter vacua. These de Sitter vacua are metastable, and decay to stable true vacuum through bubble nucleation. Even though bubbles form continuously, de Sitter regions may not dissapear due to their expansion. This is called eternal inflation. Our universe was most likely created by a bubble nucleation in eternal inflation. In this talk, I will first study fluctuations in a universe created by bubble nucleation, and see how the presence of the false vacuum affects the observables. I will use this result to find a holographic dual description defined at the boundary. Next I will study bubble collisions. I show that there are three phases in eternal inflation depending on the bubble nucleation rate. These phases are characterized by the percolating pattern of bubbles in the false vacuum. In the last part, I will touch upon the measure problem (i.e. what kind of universe is likely to be realized). In eternal inflation, infinitely many bubbles form eventually, and the answer strongly depends on the late time cutoff. One of the motivations for constructing a holographic dual is to get a clue to this problem. Main Refs.: B. Freivogel, Y. Sekino, L. Susskind and C.-P. Yeh, hep-th/0606204; Y. Sekino, S. Shenker and L. Susskind, 1003.1347 [hep-th]. | ||
(Chair: Takeshi Chiba) | ||
| 14:00 -- 15:00 | Sachiko Kuroyanagi | Gravitational waves from inflation |
(Chair: Danny Marfatia) | ||
| 16:00 -- 16:30 | Matthew Lake | Mimicking extra-dimensional effects withfield-theoretic structure in cosmic strings |
| 16:40 -- 17:10 | Yuko Urakawa | Gauge artifacts in the primordial bispectrumand holographic non-Gaussianity |
| Abstract: The conventional cosmological perturbation theory has been performed under the assumption that we know the whole spatial region of the universe with infinite volume. This is, however, not the case in the actual observations because observable portion of the universe is limited. To give a theoretical prediction to the observable fluctuations, gauge-invariant observables should be composed of the information in our local observable universe with finite volume. From this point of view, we reexamine the primordial non-Gaussianity in single-field and multi-field models, focusing on the bispectrum in the squeezed limit. It turns out that the conventional bi-spectrums are dominated by gauge artifacts, which cannot be observed. We also study primordial spectrums in a holographic context. Using the holographic description, we study primordial spectrums which preserves the gauge-invariance in the local universe. | ||
| (Chair: Shinji Mukohyama) | ||
| 09:30 -- 11:30 | Nobuyuki Kanda | Status of LCGT and the Prospect of Gravitational Wave Observation |
| Abstract: We will report a design and current construction status of LCGT (Large-scale Cryogenic Gravitational-wave Telescope) with fundamental introduction to the gravitational wave detection at first half of the talk. In last half, we will talk about the science of typical gravitational wave sources not only by observation using 'world wide network of gravitational wave detectors' but also by counterpart observations such as gamma-ray, X-ray, optical, neutrino etc. The aim of the talk is sharing the prospect of 'gravitational wave astronomy'. | ||
(Chair: Misao Sasaki) | ||
| 19:00 -- 20:30 | Tomo Takahashi | Cosmology of moduli |
| (Chair: Hideo Kodama) | ||
| 09:00 -- 10:30 | Tetsutaro Higaki | Moduli stabilization and supersymmetry breaking for string phenomenology [ppt] |
| Abstract: We will discuss moduli stabilization including light string theoretic axions based on the 4d N = 1 supergravities at the low energies, assuming that almost moduli are stabilized near the supersymmetric location. We will discuss the applications to the supersymmetric phenomenology, too. | ||
| 10:50 -- 11:50 | Kazunori Nakayama | Phenomenological Aspects of Polonyi/Moduli Problem |
| Abstract: I will summarize current situation of the cosmological Polonyi/moduli problem and then explain possible solutions to the problem. Phenomenological implications, including baryogenesis, dark matter and SUSY breaking mechanism, will also be discussed. | ||
(Chair: Tetsuya Shiromizu) | ||
| 14:30 -- 15:30 | Shinya Tomizawa | General Black Hole Solutions in D=5 SUGRA [ppt] |
| Abstract: Dimensional reduction of the five-dimensional minimal supergravity to four dimensions leads to a theory with a massless axion field and dilaton field coupled to gravity, two Maxwell fields and Chern-Simons term, whose field equations have SL(2,R) invariance. Utilizing the SL(2,R)-duality of the two electromagnetism coupled to an axion and a dilaton, we construct new solution-generation-technique. As an example, applying it to the Rasheed solutions, which are known to describe dyonic rotating black holes from a four-dimensional point of view in the five-dimensional pure gravity, we obtain rotating Kaluza-Klein black hole solutions in the bosonic sector of the five-dimensional minimal supergravity. We also show that the solutions have six charges, the mass and angular momentum, Kaluza-Klein electric charge and magnetic charge, electric charges, magnetic charge for Maxwell field, four of which are shown to be related. | ||
(Chair: Akihiro Ishibashi) | ||
| 16:00 -- 17:30 | Tsuyoshi Houri | Hidden Symmetry of Supergravity Black Holes [ppt] |
| (Chair: Nobuyoshi Ohta) | ||
| 09:00 -- 10:30 | Masahide Yamaguchi | Variation of fundamental constants |
| Abstract: I am going to review recent study of variation of fundamentall constants. | ||
| 10:50 -- 11:50 | Tatsuo Azeyanagi | Kerr/CFT対応とその拡張について |
(Chair: Kazuo Hosomichi) | ||
| 14:30 -- 15:30 | Teruhiko Kawano | F理論と大統一理論 (I) |
(Chair: Shigeki Sugimoto) | ||
| 16:00 -- 17:30 | Tohru Eguchi | 江口ーハンソン解とその周辺 |
| Abstract: ユークリッド領域のアインシュタイン方程式で知られる江口ーハンソン解について、その発見のいきさつやその拡張、超弦理論における役割などを紹介する。 | ||
| (Chair: Kazuo Hosomichi) | ||
| 09:00 -- 11:00 | Teruhiko Kawano | F理論と大統一理論(II) |
(Chair: Kazumi Okuyama) | ||
| 17:00 -- 17:40 | Sanefumi Moriyama | Summing Up All Genus Free Energy of ABJM Matrix Model [ppt] |
| Abstract: 局所化公式によってABJMの分配関数が行列模型に帰着された。ここでは全摂動項を足し上げることに成功し、示唆に富む関数で書けることがわかった。この結果に対して量子重力的な解釈を試みた。 | ||
(Chair: Koji Hashimoto) | ||
| 19:00 -- 20:30 | Yasuyuki Hatsuda | エンタングルメント・エントロピーとホログラフィー |
| (Chair: Yoichi Kazama) | ||
| 09:00 -- 10:30 | Katsushi Ito | グルーオン散乱振幅と熱力学的ベーテ仮説 (I) |
| 10:50 -- 12:20 | Katsushi Ito | グルーオン散乱振幅と熱力学的ベーテ仮説 (II) |
(Chair: Satoshi Yamaguchi) | ||
| 16:00 -- 16:40 | Taro Kimura | Instanton counting on ALE spaces and root of unity limit of q-Nekrasov function |
| Abstract: The orbifold generalization of the partition function, which would describe the gauge theory on the ALE space, is investigated from the combinatorial perspective. It is shown that the root of unity limit of the q-deformed partition function plays a crucial role on the orbifold projection. We will also discuss the relation to Macdonald polynomial and its root of unity limit. This talk is based on [arXiv:1105.6091]. | ||
| 16:50 -- 17:30 | Noriaki Ogawa | Holographic Entanglement Entropy for AdS Soliton Geometries in Higher Derivative Gravities |
| (Chair: Tohru Eguchi) | ||
| 09:00 -- 10:00 | Hiroaki Kanno | Instanton partition function (with a general surface operator) and Whittaker vector of W algebra |
| Abstract: 一般的な面作用素を入れた場合に N=2 超対称ゲージ理論の インスタントンの数え上げを考える。オービフォルド作用付きの ADHM 構成法により、モジュライ空間がある種のクイバーの表現を 用いて記述できることを説明する。さらに時間が許せば、 局所化公式により計算される分配関数と一般化 W 代数の表現の 関係を議論したい。 | ||
(Chair: Teruhiko Kawano) | ||
| 10:30 -- 12:00 | Kentaro Hori | Introduction to linear sigma models (lecture I) |
| 16:00 -- 17:30 | Kentaro Hori | Introduction to linear sigma models (lecture II) |
| (Chair: Hiroaki Kanno) | ||
| 09:00 -- 10:00 | Masahito Yamazaki | 三次元超対称ゲージ理論と双曲幾何 |
| 10:10 -- 10:50 | Takahiro Nishinaka | Affine SU(N) algebra from wall-crossings |
| Abstract: Recently, there has been remarkable progress in the study of wall-crossing phenomena of D-branes. In particular, it has been shown that instanton partition functions on D4-branes with different topologies can be connected by wall-crossings. In this talk, I will extend this argument to a D4-brane on A_{N-1} ALE space, whose instanton partition function is known to be given by the character of affine SU(N) algebra. I will explicitly show that the affine SU(N) character can be obtained from the instanton partition function on C^2, by considering the wall-crossing of D4-D2-D0 states. This talk is based on a work in collaboration with Satoshi Yamaguchi. | ||