2014年度セミナー (Seminar Schedule 2014)
SCQM from M2-branes
| When: | 2014/04/16 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Tadashi Okazaki (Caltech / Osaka Univ.) |
| Abstract: | The BLG-model and the ABJM-model are expected to describe flat multiple M2-branes. We consider the situations where the M2-branes wrap on a holomorphic two-cycle in a Calabi-Yau space. We study the arising one-dimensional quantum mechanics by taking the limit where the size of the holomorphic curve goes to zero. The talk will be based on a joint work in progress with Hirosi Ooguri. |
| Reference: |
AdS/CFT対応で探る非平衡定常系の有効温度
| When: | 2014/04/23 (Wed.) 16:30-17:30 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Shin Nakamura (Chuo Univ.) |
| Abstract: | 現代物理学における未開拓の分野に非平衡系の統計物理学がある。平衡系の統計物理学では、多自由度系を統計的に記述することで、成功を収めたが、非平衡系、特に外力への応答が非線形な領域の、平衡から離れた系の統計物理学を構成することは、現代物理学の重要な課題として残っている。本研究では、外力によって非線形領域にドライブされたゲージ粒子の多自由度系を、AdS/CFT対応によって重力理論にマップし、系の統計的振る舞いを調べる。特に、巨視的には時間変化のない非平衡定常系に注目し、平衡系で重要な役割をした温度の概念が非平衡定常系においても存在するか、また存在するとしたらどのような振る舞いをするのか、について解析する。興味深いことに、少なくともある種の非平衡定常系では、重力理論にマップすると、揺らぎの自由度が観測する有効ホライズンが現れ、そこでのホーキング温度から有効温度を自然に定義できることが分かる。講演では、この有効温度の興味深い振る舞いについて報告する。 |
| Reference: | S. Nakamura and H. Ooguri, Phys. Rev. D88 (2013) 126003 [arXiv:1309.4089]. |
Emergent bubbling geometries in the plane wave matrix model
| When: | 2014/04/30 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Yuhma Asano (Kyoto Univ.) |
| Abstract: | According to gauge/gravity correspondences, emergence of the space-times should be observed in the framework of the corresponding gauge theories. This is a quite important problem from the viewpoint of the non-perturbative effects of superstring theories. In this talk, I will discuss the plane wave matrix model as an example and show how the corresponding space-times emerge. The gauge/gravity correspondence for the plane wave matrix model was conjectured by Lin and Maldacena [1], and the gravity solutions were constructed. By applying the localization method to a quarter BPS sector of the plane wave matrix model [2], we find that the eigenvalue distributions in the plane wave matrix model actually produce the corresponding geometries. This talk is based on the collaboration with G. Ishiki, T. Okada and S. Shimasaki [3]. |
| Reference: | [1] H. Lin and J. M. Maldacena, Phys. Rev. D 74, 084014 (2006) [2] Y. Asano, G. Ishiki, T. Okada, S. Shimasaki, JHEP 1302, 148 (2013) [3] Y. Asano, G. Ishiki, T. Okada, S. Shimasaki, arXiv:1401.5079 |
Superspace with manifest T-duality from type II superstring
| When: | 2014/05/09 (Fri.) 13:30-14:30 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Machiko Hatsuda (Juntendo Univ. / KEK) |
| Abstract: | A superspace formulation of type II superstring background with manifest T-duality symmetry is presented.This manifestly T-dual formulation is constructed in a space spanned by two sets of nondegenerate super-Poincare algebra.Supertorsion constraints are obtained from consistency of the kappa-symmetric Virasoro constraints.All superconnections and vielbein fields are solved in terms of a prepotential which is one of the vielbein components. AdS5xS5 background is explained in this formulation. |
| Reference: | Machiko Hatsuda, Kiyoshi Kamimura, Warren Siegel arXiv:1403.3887 |
On the Entanglement of Multiple CFTs via Rotating Black Hole Interior
| When: | 2014/05/14 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Noriaki Ogawa (RIKEN) |
| Abstract: | We study the minimal surfaces between two of the multiple boundaries of 3d maximally extended rotating eternal black hole. Via AdS/CFT, this corresponds to investigating the behavior of entanglements of the boundary CFT with multiple sectors. Non-trivial time evolutions of such entanglements detect the geometry inside the horizon, and behave differently depending on the choice of the two boundaries. (Based on arXiv:1402.4548, with Norihiro Iizuka) |
| Reference: | arXiv:1402.4548 |
F-theory Family Unification
| When: | 2014/05/21 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Shun'ya Mizoguchi (KEK) |
| Abstract: | We propose a new geometric mechanism for naturally realizing unparallel three families of flavors in string theory, using the framework of F-theory. We consider a set of coalesced local 7-branes of a particular Kodaira singularity type and allow some of the branes to bend and separate from the rest, so that they meet only at an intersection point. Such a local configuration can preserve supersymmetry. Its matter spectrum is investigated by studying string junctions near the intersection, and shown to coincide, after an orbifold projection, with that of a supersymmetric coset sigma model whose target space is a homogeneous Kahler manifold associated with a corresponding painted Dynkin diagram. In particular, if one starts from the $E_7$ singularity, one obtains the $E_7/(SU(5) \times U(1)^3)$ model yielding precisely three generations with an unparallel family structure. Possible applications to string phenomenology are also discussed. |
| Reference: | Shun'ya Mizoguchi, arXiv:1403.7066 |
Stückelberg-BRST Approach to the No-Ghost Theorem in Massive Gravity
| When: | 2014/05/28 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Taichiro Kugo (KSU) |
| Abstract: | 重力場の質量項は、重力をシールドする効果を持つので、それがあれば宇宙項問題にも重大な効果を持つ。しかし、Einstein重力理論に質量項を加えてmassive gravity理論にすると、ghost問題や、ゼロ質量極限にスムースにつながらないなど様々な問題を生じる。ここでは、特に、deRham-Gabadadze-Tolleyの提唱したnonlinear massive gravity理論において、Stückelberg場を導入して隠れた局所対称性を持たせた定式化を用いて、任意の背景時空上でghostが現れないことを証明する。 |
| Reference: | T. Kugo and N. Ohta, ``Covariant Approach to the No-ghost Theorem in Massive Gravity,'' PTEP 2014 4, 043B04 [arXiv:1401.3873 [hep-th]]. |
Boundary effects on the supersymmetric sine-Gordon model through light-cone lattice approach
| When: | 2014/06/11 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Chihiro Matsui (Univ. of Tokyo) |
| Abstract: | We discussed subspaces of the N=1 supersymmetric sine-Gordon model with Dirichlet boundaries through light-cone lattice regularization. In this paper, we showed, unlike the periodic boundary case, both of Neveu-Schwarz (NS) and Ramond (R) sectors of a superconformal field theory were obtained. Using a method of nonlinear integral equations for auxiliary functions defined by eigenvalues of transfer matrices, we found that an excitation state with an odd number of particles is allowed for a certain value of a boundary parameter even on a system consisting of an even number of sites. In a small-volume limit where conformal invariance shows up in the theory, we derived conformal dimensions of states constructed through the lattice-regularized theory. The result shows existence of the R sector, which cannot be obtained from the periodic system, while a winding number is restricted to an integer or a half-integer depending on boundary parameters. |
| Reference: | arXiv:1404.3809 |
Construction of Gaiotto states with fundamental multiplets through Degenerate DAHA
| When: | 2014/07/04 (Fri.) 13:30-14:30 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Yutaka Matsuo (Univ. of Tokyo, Hongo) |
| Abstract: | We construct Gaiotto states with fundamental multiplets in SU(N) gauge theories, in terms of the orthonormal basis of spherical degenerate double affine Hecke algebra (SH in short), the representations of which are equivalent to those of Wn algebra with additional U(1) current. The generalized Whittaker conditions are demonstrated under the action of SH, and further rewritten in terms of Wn algebra. Our approach not only consists with the existing literature but also holds for general SU(N) case. |
| Reference: | Y. Matsuo, C. Rim, H. Zhang, "Construction of Gaiotto states with fundamental multiplets through Degenerate DAHA," [arXiv:1405.3141[hep-th]]. |
Kadanoff-Baym/density matrix approach to resonant leptogenesis
| When: | 2014/07/09 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Kengo Shimada (Sokendai(KEK)) |
| Abstract: | レプトジェネシスはマヨラナ質量を持つ右巻きニュートリノの崩壊により宇宙のバリオン数を説明するものであり、同時にシーソー機構によって有限のニュートリノ質量を説明する。 このシナリオのなかでマヨラナ質量をTeV程度にまで下げ、実験検出可能なモデルを作るためには、二つの右巻きニュートリノの質量を縮退させ、それらのフレーバー振動によって崩壊過程におけるCP非対称性を増幅させる必要がある(レゾナントレプトジェネシス)。 この非平衡過程で生成されるレプトン数は、これまで古典的なボルツマン方程式と平衡場の量子論を組み合わせることにより計算されてきたが、量子効果と非平衡性を一つの枠組みの中で扱うことで、より正しい結果が得られると期待される。 本講演では、そのような枠組みとして、Kadanoff-Baym方程式とDensity matrix formalismを取り上げ、レゾナントレプトジェネシスにおけるCP非対称性の増幅が変更されることを示す。 |
| Reference: | arXiv:1404.4816[hep-ph], arXiv:1312.7680[hep-ph]. |
AdS_4/CFT_3におけるトーリック図と自由エネルギーの関係
| When: | 2014/07/28 (Mon.) 13:30-14:30 |
|---|---|
| Where: | Honkan (Main Bldg.) H1-56 |
| Speaker: | Daisuke Yokoyama (SNU) |
| Abstract: | M2ブレーンを記述する有効理論は３次元の共形ゲージ理論と４次元AdSを背景に持つ重力理論である。局所化法の発展によってゲージ理論側から自由エネルギーが厳密に計算されるようになり、いくつかの例に関してlarge N 極限における値も評価されている。本発表ではこの自由エネルギーを重力側から求める手法について議論する。ゲージ理論の違いは重力側では背景空間(７次元の内部空間)の違いとして現れる。この空間と関係するトーリック図と自由エネルギーの間にある関係、つまりトーリック図から自由エネルギーを求める公式について説明する。また、時間があれば重力理論（背景空間上の場の自由度）と自由エネルギーの間の関係についても議論する。 |
| Reference: |
E型弦理論のアノマリ多項式
| When: | 2014/07/30 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Hiroyuki Shimizu (Univ. of Tokyo, Hongo) |
| Abstract: | 6次元超共形場理論のアノマリ多項式は、これらの強結合理論に対して厳密に計算が可能な数少ない物理量の1つであるが、その正確な表式は最大の超対称性を持つ(2,0)理論の場合にしか知られていない。 本発表では、超対称性がより少ない6次元(1,0)超共形場理論の一つであるE型弦理論に対して、M理論による構成を用いてアノマリ多項式を求める方法を解説する。時間があれば、より広いクラスの6次元(1,0)超共形場理論に対してアノマリ多項式を決定する新たな場の理論的な手法についても紹介したい。 |
| Reference: | K.Ohmori, H.Shimizu, Y.Tachikawa arXiv:1404.3887 |
Defect scaling Lee-Yang model from the perturbed DCFT point of view
| When: | 2014/10/01 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Holló László (Wigner Research Centre for Physics) |
| Abstract: | We analyze the defect scaling Lee-Yang model from the perturbed defect conformal field theory (DCFT) point of view. First the defect Lee-Yang model is solved by calculating its structure constants from the sewing relations. Integrable defect perturbations are identified in conformal defect perturbation theory. Then pure defect flows connecting integrable conformal defects are described. We develop a defect truncated conformal space approach (DTCSA) to analyze the one parameter family of integrable massive perturbations in finite volume numerically. Fusing the integrable defect to an integrable boundary the relation between the IR and UV parameters can be derived from the boundary relations. We checked these results by comparing the spectrum for large volumes to the scattering theory. |
| Reference: | arXiv:1307.4536 |
Superconformal index on RP^2 x S^1
| When: | 2014/10/08 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Akinori Tanaka (Osaka Univ.) |
| Abstract: | We study N=2 supersymmetric gauge theories on RP^2 x S^1 and compute the superconformal index by using the localization technique. We apply our new superconformal index to the check of the simplest 3d mirror symmetry and prove it by using a mathematical formula called the q-binomial theorem. In this talk, I would like to explain the crucial points of our work and comment on some generalizations. |
| Reference: | arXiv:1408.3371 |
WZW-like action for NS-NS string field theory
| When: | 2014/10/15 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Hiroaki Matsunaga (Univ. of Tokyo, Komaba) |
| Abstract: | 超弦の場の理論は 超弦理論の非摂動的な理解へむけたアプローチの一つであるが、定式化の途上にある。特に、発散のないゲージ不変な作用の構成は課題の一つであったが、近年NSセクター・NS-NSセクターを記述する作用が構成され、現在その定式化は進展をみせている。 本発表では、NS-NSセクターを記述する作用の構成とそのゲージ対称性について解説する。作用の構成には２つの異なる手法が知られているが、ここでは主にWZW形式に基づく手法を説明する。 時間があれば、他の手法との関係についても紹介したい。 |
| Reference: | arXiv:1407.8485 |
Topologically-twisted 2D SYM on general lattice discretizations and its exact results
| When: | 2014/10/22 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Tatsuhiro Misumi (Keio Univ.) |
| Abstract: | Some of lattice models for 2D extended supersymmetric theories are formulated so as to have Q-exact action under scalar superchrage Q (BRST charge). We show that such Q-exact lattice theories, which are usually defined on the square lattices, can be extended to more general lattices characterized just by the Euler characteristic (# sites - # links + # faces). We discuss its continuum limit and its relation to topological field theory on the curved background. On the other hand, it is well-known that some of physical quantities are exactly calculable in certain supersymmetric theories via the ``localization" technique. We apply the localization technique to our theories and show that the exact partition functions only depends on the topology of the background manifold. Regarding further investigations and applications of our works, we discuss several implications of our results: 1)lattice formulations of (topological) field theories on the curved background, 2)simplification of numerical analysis of the SUSY lattice models, 3)potential relation to the quiver matrix models. |
| Reference: |
Entanglement Entropy of Local operator excited states in CFTs
| When: | 2014/11/05 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Tokiro Numasawa (YITP) |
| Abstract: | Entanglement entropy is a helpful observable that can detect the geometry of wave function in quantum field theories. When we consider an excited state, its time evolution of the entanglement entropy characterizes the time evolution of the state. In this talk,we will explain how to calculate the entanglement entropy of excited states defined by acting local operator on the vacuum state and show several analytical results for free scalar fields in various dimensions and for 2d rational CFTs. |
| Reference: | arXiv:1401.0539 arXiv:1403.0702 |
Exact Results in Quiver Quantum Mechanics and BPS Bound State Counting
| When: | 2014/11/19 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Kazutoshi Ohta (Meiji Gakuin Univ.) |
| Abstract: | We exactly evaluate the partition function (index) of N=4 supersymmetric quiver quantum mechanics in the Higgs phase by using the localization techniques. We show that the path integral is localized at the fixed points, which are obtained by solving the BRST equations, and D-term and F-term conditions. We turn on background gauge fields of R-symmetries for the chiral multiplets corresponding to the arrows between quiver nodes, but the partition function does not depend on these R-charges. We give explicit examples of the quiver theory including a non-coprime dimension vector. The partition functions completely agree with the mathematical formulas of the Poincare polynomials and the wall crossing for the quiver moduli spaces . We also discuss exact computation of the expectation values of supersymmetric (Q-closed) Wilson loops in the quiver theory. |
| Reference: | arXiv:1408.0582 |
Emergent bubbling geometry in gauge theories with SU(2|4) symmetry
| When: | 2014/11/26 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Goro Ishiki (Univ. of Tsukuba) |
| Abstract: | We study the gauge/gravity duality between bubbling geometries in type IIA supergravity and gauge theories with SU(2|4) symmetry, which consist of ${\mathcal N}=4$ super Yang-Mills on ${\mathbb R} \times S^3/{\mathbb Z}_k$, ${\mathcal N} = 8$ super Yang-Mills on ${\mathbb R} \times S^2$ and the plane wave matrix model. We show that the geometries on the gravity side are realized as field configurations in the strong coupling region of the gauge theories. On the gravity side, the bubbling geometries can be mapped to electrostatic systems with some conducting disks. On the gauge theory side, we obtain matrix integrals by applying the localization to 1/4-BPS sectors of the gauge theories. We show that in the strong coupling limit the classical action of the matrix integral is equivalent to the action of the electrostatic system on the gravity side. This equivalence connects the DOF on the gauge theories to the background geometries, namely the eigenvalue densities in the gauge theories form the background geometry in the corresponding string theories. |
| Reference: | JHEP 1409 (2014) 137, JHEP 1405 (2014) 075, JHEP 1302 (2013) 148 |
On quantum corrections of a string world sheet for a Wilson loop in the AdS/CFT correspondence
| When: | 2014/12/03 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Akitsugu Miwa (Nihon Univ.) |
| Abstract: | Correspondences between a Wilson loop operator and a string world sheet have been well studied in the context of the AdS/CFT correspondence. However, checking the correspondences by taking account of quantum effects of the string world sheet does not seem to be very successful. We reconsider one of the method of studying the quantum effects, and apply it to a correlation function of the Wilson loop and a local operator. |
| Reference: |
Argyres-Douglas theories and S-duality
| When: | 2014/12/04 (Thu.) 13:30-14:30 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Takahiro Nishinaka (Rutgers University) |
| Abstract: | We study the generalization of S-duality for 4d N=2 superconformal gauge theories coupled to Argyres-Douglas type SCFT's. The Argyres-Douglas theories are isolated 4d N=2 SCFT's without known Lagrangian description, which often have a non-abelian flavor symmetry. We gauge the flavor symmetry together with additional hypermultiplets so that the gauging is exactly marginal. We find that the theory at the strong gauge coupling has another weak coupling description. This is a natural generalization of the Argyres-Seiberg-Gaiotto duality to theories coupled to Argyres-Douglas theories. |
| Reference: | arXiv:1411.6026 |
Fiber-Base Duality and Global Symmetry Enhancement
| When: | 2014/12/17 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Masato Taki (RIKEN(iTHES)) |
| Abstract: | We show that the 5D Nekrasov partition functions enjoy the enhanced global symmetry of the UV fixed point. The fiber-base duality is responsible for the global symmetry enhancement. For SU(2) with Nf≤7 flavors the fiber-base symmetry together with the manifest flavor SO(2Nf) symmetry generate the ENf+1 global symmetry, while in the higher rank case the manifest global symmetry of the two dual theories related by the fiber-base duality map generate the symmetry enhancement. The symmetry enhancement at the level of the partition function is manifest once we chose an appropriate reparametrization for the Coulomb moduli. |
| Reference: | arXiv:1411.2450 arXiv:1310.3841 |
Recent progress in the q-deformed AdS_5 x S^5 superstring
| When: | 2015/01/14 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Takashi Kameyama (Kyoto University) |
| Abstract: | We study a GKP-like classical string solution on a q-deformed AdS_5 x S^5 background and argue the spacetime structure by using it as a probe. The solution cannot stretch beyond the singularity surface and this result may suggest that the holographic relation is realized inside the singularity surface. This observation leads us to introduce a new coordinate system which describes the spacetime only inside the singularity surface. With an appropriate analogue of Poincare coordinates, we study minimal surfaces whose boundary shape is a circle. A solution corresponds to a 1/2 BPS circular Wilson loop in the undeformed limit. A remarkable point is that the classical Euclidean action is not divergent unlike the original one. The finiteness comes from the fact that the q-deformation may be regarded as a UV regularization. |
| Reference: | arXiv:1408.2189, arXiv:1410.5544 |
4d N=1 SCFTs from M5-branes
| When: | 2015/01/20 (Tue.) 13:30-14:30 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Kazunobu Maruyoshi (Imperial College London) |
| Abstract: | We discuss a large class of 4d N=1 gauge theories, which flows to nontrivial IR fixed point, from M5-brane compactification on a Riemann surface. We find that various remarkable properties of this class of theories, like duality, can be understood in terms of the Riemann surface and leads to discovery of unknown dualities in N=1 theories. |
| Reference: |
Pomeranskyの改良型逆散乱法によって生成される重力ソリトン解
| When: | 2015/01/21 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Shinya Tomizawa (Tokyo Univ. of Tech.) |
| Abstract: | 連立非線形偏微分方程式系であるアインシュタイン方程式の厳密解を求めることは、一般的に容易ではない。2006年、Pomerankyの改良した逆散乱法によって、ソリトン解としてブラックリング解が発見されたことを契機に、多くの高次元ブラックホール解が発見されてきた。本研究では、この改良型逆散乱法を初めて円筒対称時空に応用し、「非線形重力波」を記述するソリトン解を求めた。本セミナーでは、まず逆散乱法のレビューをし、本研究で求めた１ソリトン解と２ソリトン解を紹介する。 |
| Reference: |
Toward construction of supergravity superstrata states
| When: | 2015/01/28 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H1-55B |
| Speaker: | Masaki Shigemori (Yukawa Institute, Kyoto University) |
| Abstract: | Superstrata are conjectural, smooth solutions of supergravity parametrized by functions two variables. Their existence has been conjectured based on multiple supertube transitions and on the dual CFT analysis, and they may represent geometric microstates of the 3-charge black hole with a finite horizon. In this talk, I present strong evidence for the existence of superstrata solutions by giving some explicit examples. |
| Reference: |
Entanglement Entropy of Annulus in Three Dimensions
| When: | 2015/02/18 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Yuki Nakaguchi (Kavli IPMU) |
| Abstract: | Entanglement entropy has recently been recognized to be useful in many purposes, for example, to construct a measure of degrees of freedom monotonically decreasing along any RG flow. However, its general behavior is not well understood because it has been analytically calculated only for limited shapes. To examine its general behavior, we numerically calculated entanglement entropies of an annular region, or its equivalent notion ``mutual information across the annular region'', by lattice discretization and by the holographic formula. As a result, we found two interesting features. One is the role of the mutual information as a measure of the UV degrees of freedom in the small width limit. The other is an exponentially small correction to the existing mass expansion formula for gapped theories. Based on these observations, we discuss a possibility that the mutual information can be a measure of degrees of freedom of field theories. |
| Reference: | arXiv:1501.01293 |
日ハンガリー二国間共同研究セミナー
| When: | 2015/03/20 (Fri.) 13:30-16:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | 川井大輔$^a$, 加藤晃史$^b$ ($^a$京大理, $^b$東大数理) |
| Abstract: | 13:30-14:30 川井大輔 Chaos in the BMN matrix model 15:00-16:00 加藤晃史 Quiver mutation loops and partition q-series |
| Reference: |