KEK Theory workshop 2019

Session

Short talks

3 Dec 2019, 14:30

Kobayashi Hall, Kenkyu-Honkan bldg. 1F (KEK)

Conveners

Short talks: Anand HEGDE, Yutaka OOKOUCHI, Yasuhiro SEKINO, Sota HANAZAWA

• Chair: Keisuke Ohashi

Short talks: Hiromasa TAKAURA, Ryo YOKOKURA, Xuanting JI, Yoshinori MATSUO

• Chair: Matsuo Sato

Short talks: Ken KIKUCHI, Yoshiki SATO, Hajime OTSUKA, Matsuo SATO

• Chair: Yutaka Ookouchi

Short talks: Yun-Long ZHANG, Keisuke OHASHI, Noburo SHIBA, Akihiro ISHIBASHI

• Chair: Yasuhiro Sekino

18. Gravitational Thomas Precession Effect as a New Cosmological Probe

Mr Anand Hegde

03/12/2019, 14:30

Thomas Precession has been extensively studied as a special relativistic effect.In this paper, we study Thomas like precession of spinning tops in the presence of gravitational fields. To establish this effect we evaluate a system whose spin is defined by a spin-four vector near a strong source of gravitational waves. It can be shown that for a system like hydrogen atom in a strong...

19. Catalytic Creation of Baby Bubble Universe with Small Positive Cosmological Constant

Prof. Yutaka Ookouchi

03/12/2019, 14:45

We investigate the decay of metastable de Sitter, Minkowski and anti-de Sitter vacua catalyzed by a black hole and a cloud of strings. We apply the method to the creation of the four dimensional bubble universe in the five dimensional anti-de Sitter spacetime recently proposed by Banerjee, Danielsson, Dibitetto, Giri and Schillo. We study the bounce action for the creation and find that the...

20. Evidence for Weak-Coupling Holography from the Gauge/Gravity Correspondence for Dp-branes

Prof. Yasuhiro Sekino

03/12/2019, 15:00

Gauge/gravity correspondence is regarded as a powerful tool for the study strongly-coupled quantum systems, but its proof is not available. An unresolved issue that should be closely related to the proof is what kind of correspondence exists, if any, when gauge theory is weakly coupled. We report progress about this limit for the case associated with D$p$-branes ($0\le p\le 4$), namely, the...

21. Supersymmetric non-abelian D-brane equations from open pure spinor superstring

Dr Sota Hanazawa

03/12/2019, 15:15

We have examined the BRS invariance of the open pure spinor superstring to derive equations of motion for a supersymmetric D$p$-brane, which should be induced from the DBI action and the Wess-Zumino action. These equations are consistent with the dimensional reduction of equations for a supersymmetric D9-brane obtained by Berkovits and Pershin. They also analyzed non-abelian backgrounds up to...

22. Renormalon in compactified spacetime and relation with bion

Dr Hiromasa Takaura

04/12/2019, 15:30

Recently, it was conjectured that the perturbative ambiguity known as the renormalon is canceled against the nonperturbative semiclassical object called bion. This conjecture expects this kind of cancellation in the circle compactified spacetime, in which the bion solution is found, as a premise. To examine this conjecture, we study the renormalon structure in the compactified spacetime under...

23. Topological order in the color-flavor locked phase of (3+1)-dimensional U(N) gauge-Higgs system

Dr Ryo Yokokura

04/12/2019, 15:45

We study a (3+1)-dimensional U(N) gauge theory with N-flavor fundamental scalar fields, whose color-flavor locked (CFL) phase has topologically stable non-Abelian vortices. The U(1) charge of the scalar fields must be Nk+1 for some integer k in order for them to be in the representation of U(N) gauge group. This theory has a Z_{Nk+1} one-form symmetry, and it is spontaneously broken in the CFL...

24. Chiral vortical conductivity across a topological phase transition from holography

Dr Xuanting Ji

04/12/2019, 16:00

We study the chiral vortical conductivity in a holographic Weyl semimetal model, which describes a topological phase transition from the strongly coupled topologically nontrivial phase to a trivial phase. We focus on the temperature dependence of the chiral vortical conductivity where the mixed gauge-gravitational anomaly plays a crucial role. After a proper renormalization of the chiral...

25. Nuclear states and spectra in holographic QCD

Dr Yoshinori Matsuo

04/12/2019, 16:15

A new method to study nuclear physics via holographic QCD is proposed. Multiple baryons in the Sakai-Sugimoto background are described by a matrix model which is a low energy effective theory of D-branes of the baryon vertices. We study the quantum mechanics of the matrix model and calculate the eigenstates of the Hamiltonian. The obtained states are found to coincide with known nuclear and...

26. 2d 't Hooft anomaly, orbifolding, and boundary states

Dr Ken Kikuchi

04/12/2019, 16:50

We study anomalies for a discrete internal global symmetry $G$ in two-dimensional conformal field theories based on twisted torus partition functions. The 't Hooft anomaly of $G$ can be seen from the noncommutativity of two symmetry lines inserted along the nontrivial circles of two-torus and we propose a criterion to detect the 't Hooft anomaly, which agrees with the truncated modular...

27. Does Boundary Distinguish Complexities?

Dr Yoshiki Sato

04/12/2019, 17:05

Recently, Chapman et al. argued that holographic complexities for defects distinguish action from volume. Motivated by their work, we study complexity of quantum states in conformal field theory with boundary. In generic two-dimensional BCFT, we work on the path-integral optimization which gives one of field-theoretic definitions for the complexity. We also perform holographic computations of...

28. Wavefunctions and Yukawa couplings on Resolutions of C^N/Z_N Orbifolds

Dr Hajime Otsuka

04/12/2019, 17:20

We propose matter wavefunctions on resolutions of C^N/Z_N singularities with magnetic fluxes. In this talk, we first discuss the resolution of magnetized T^2/Z_N orbifold models. In the blow-down limit of T^2/Z_N orbifolds, the obtained wavefunctions of chiral zero-modes result in those on the magnetized T^2/Z_N orbifold models, but only the wavefunctions of Z_N-invariant zero-modes receive...

29. String Geometry Phenomenology

Prof. Matsuo Sato

04/12/2019, 17:35

String geometry theory is one of candidates of the non-perturbative formulation of string theory. In order to derive low-energy phenomena, we first need to clarify how supergravity background fields, which represent the space-time and the internal space, are described in string geometry theory. In this presentation, we show that arbitrary configurations of the heterotic supergravity background...

30. Hyperbolic Field Space and Swampland Conjecture for DBI Scalar

Dr Yun-Long Zhang

05/12/2019, 13:30

We study a model of two scalar fields with a hyperbolic field space and show that it reduces to a single-field Dirac-Born-Infeld (DBI) model in the limit where the field space becomes infinitely curved. We apply the de Sitter swampland conjecture to the two-field model and take the same limit. It is shown that in the limit, all quantities appearing in the swampland conjecture remain...

31. Duality Invariance of Kahler potentials on Generalized Flag Manifolds from Diverse Quiver Gauge Theories

Dr Keisuke Ohashi

05/12/2019, 13:45

We present a systematic construction of K¨ahler potentials for various quiver gauge theories, which give pure realizations of the general flag manifolds as target manifolds. There, for arbitrary gener- alized flag manifolds with arbitrary complex structures, we rediscover the K¨ahler potentials given in the basic theory by Bando, Kuramoto, Maskawa and Uehara. In terms of these explicit forms,...

32. Direct Calculation of Mutual Information of Distant Regions

Dr Noburo Shiba

05/12/2019, 14:00

We consider the (Renyi) mutual information, I^(n) (A,B)=S^(n)_A +S^(n)_B −S^(n)_ A∪B , of distant compact spatial regions A and B in the vacuum state of a free scalar field. The distance r between A and B is much greater than their sizes R A,B . It is known that I^(n)_(A,B)∼C^(n)_AB ⟨0|ϕ(r)ϕ(0)|0⟩^2 . We obtain the direct expression of C^(n)_AB for arbitrary regions A and B. We perform the...

33. Quantum null energy condition, weak cosmic censorship, and holography

Dr Akihiro Ishibashi

05/12/2019, 14:15

We discuss the compatibility of AdS/CFT duality with the bulk and boundary causality which asserts that the fastest null geodesic connecting any two boundary points must lie entirely on the boundary. We show that if this type of causality fails without breaking the averaged null energy condition (ANEC), the weak cosmic censorship must be violated. We also discuss relationships between the bulk...