KEK Theory workshop 2019

Session

Poster

5 Dec 2019, 15:00

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

35. A possible solution to the black hole puzzle in semi-classical gravity

Prof. Takeshi Morita

05/12/2019, 15:00

We discuss that the black hole geometry around the event horizon in semi-classical gravity could be significantly different from that of the classical one. This is due to the Hawking radiation of the higher angular momentum modes of matter fields that was believed to be irrelevant.

59. Application of the tensor renormalization group method to non-Abelian lattice gauge theories

Mr Atis Yosprakob

05/12/2019, 15:00

The tensor renormalization group method is a powerful tool to study lattice models, which works even with models that have sign problem. However, so far, its application to gauge theory has been restricted the U(1) and SU(2) cases. In this work, we apply it to two-dimensional U(N) gauge theories which are exactly solvable. We are able to extract the large-N behaviors of the model such as...

39. Cancellation of one-loop corrections to scalar masses in Yang-Mills theory with flux compactification

Mr Takuya Hirose

05/12/2019, 15:00

We calculate one-loop corrections to the mass for the zero mode of scalar field in a six-dimensional Yang-Mills theory compactified on a torus with magnetic flux. It is shown that these corrections are exactly cancelled thanks to a shift symmetry under the translation in extra spaces. This result is expected from the fact that the zero mode of scalar field is a Nambu-Goldstone boson of the...

47. Complex Langevin Simulation of 2D U(1) gauge theory with a theta term

Mr Akira Matsumoto

05/12/2019, 15:00

The Monte Carlo simulation of gauge theories with a theta term is quite difficult due to the sign problem. The complex Langevin method is a promising approach to solve this problem. We applied this method to the 2D U(1) gauge theory, which is analytically solvable, in order to check the validity of the method. We were able to reproduce the exact results in the whole region of -pi <= theta <=...

60. Complex Langevin simulation of the Lorentzian type IIB matrix model

Mr Mitsuaki HIRASAWA (SOKENDAI)

05/12/2019, 15:00

The type IIB matrix model has been studied as a candidate of non-perturbative formulation of superstring theory. In particular, by Monte Carlo simulation of the Lorentzian type IIB matrix model, (3+1)-dimensional expanding space-time was shown to emerge dynamically. With its detailed analysis, we found that the emergent 3-dimensional space is essentially described by the Pauli matrices, we...

51. Complex poles and spectral functions of Landau gauge QCD and QCD-like theories

Ms Yui Hayashi

05/12/2019, 15:00

We investigate the analytic structures of the gluon and quark propagators of an effective model of the Landau gauge QCD and QCD with many quark flavors, which can be obtained by adding effective mass terms to the standard Faddeev-Popov Lagrangian. We derive general relationships between the number of complex poles and the sign of the spectral function under some assumptions on the asymptotic...

38. Cubic vertices for massless higher spin gauge fields in AdS spaces

Mr Haruya Suzuki

05/12/2019, 15:00

Higher spin (HS) gauge theory may be regarded as a generalization of the electromagnetic theory of a spin-1 photon and the linearized gravity of a spin-2 graviton. String theory which has infinitely many massive modes may be seen as a broken phase of the HS gauge symmetry. The higher spin gauge theory is expected to gain a deeper understanding of AdS/CFT duality. To gain more insight into the...

41. D3-brane analysis for the superconformal index in orbifold quiver gauge theories

Mr Shota Fujiwara

05/12/2019, 15:00

We study the orbifold type of AdS5/CFT4 correspondence for finite N by using the superconformal index. Especially, we calculate the finite N corrections to the superconformal index from the dual gravity theory. Our method is based on the assumption that D3-branes wrapped around three-cycles in the internal space reproduce the finite N corrections. As a result we find this approach actually gives...

49. Double field inflation of generalized dilaton-axion models with a new Fayet-Iliopoulos (FI) term

Mr Ping Kwan Man

05/12/2019, 15:00

In this talk, we are going to talk about inflation dynamics by KKLT-like model modified by a new Fayet-iliopoulos (FI) term. KKLT model, motivated by superstring theory, gives the AdS vacuum, which is phenomenologically forbidden. Although previous studies solved this problem by adding a D3 bar or D7 contribution to uplift the vacuum to zero, it is not flat enough to provide the initial...

45. Dynamics of Revolving D-Branes at Short Distances

Mr Hikaru Ohta

05/12/2019, 15:00

We study the behavior of the effective potential between revolving Dp-branes at all ranges of the distance $r$, interpolating regions on which r is larger and smaller than the string length. Since the one-loop open string amplitude cannot be calculated exactly, we instead employ an efficient method of partial modular transformation. The method is to perform the modular transformation partially...

50. Emergent quantum spacetime from stochastic processes of matrix models

Mr Nobuyuki Matsumoto

05/12/2019, 15:00

Towards formulating quantum gravity, we present a mechanism of the emergence of spacetime geometry from randomness. In [Fukuma-NM-Umeda, [arXiv:1705.06097]], we defined for a given stochastic process "the distance between configurations," which enumerates the difficulty of transition. In this talk, we consider large-N matrix models, in which we regard eigenvalues as spacetime coordinates. We...

57. Entropy generation and decay of the cosmological constant in Liouville gravity

Dr Kitamoto Hiroyuki

05/12/2019, 15:00

We investigated quantum infrared dynamics in 2D Liouville gravity with a positive cosmological constant and a large central charge $c>25$. Superhorizon fluctuations of the conformal mode of the metric dynamically screen the cosmological constant, and the dS entropy increases simultaneously. We can identify the dS entropy with the von Neumann entropy of the conformal zero mode. This quantum...

42. Finite N corrections to the superconformal index of toric quiver gauge theories

Mr Tatsuya Mori

05/12/2019, 15:00

We study the finite N AdS/CFT correspondence between the Type IIB string theories on AdS5×SE5 and quiver gauge theories, where SE5 is a five-dimensional Sasaki-Einstein manifold. Our assumption is that D3-branes wrapping on the three-cycles in the internal space give the finite N corrections to the index. We calculate the index of wrapped D3-branes and get the non-trivial coincidence for...

54. From 3d dualities to hadron physics

Mr Naoto Kan

05/12/2019, 15:00

When one of the space-time dimension is compactified on the circle, the QCD exhibits the chiral phase transition at some critical radius. When we further turn on a background theta term which depends on the compactified coordinate, a topological ordered phase appears at low energy via the winding of the theta. We discuss what kind of theories can describe the physics near the critical point by...

40. Higher spin symmetry in the IIB matrix model with the operator interpretation

Mr Katsuta Sakai

05/12/2019, 15:00

We study the IIB matrix model in an interpretation where the matrices are differential operators defined on curved spacetimes. In this interpretation, coefficients of higher derivative operators formally appear to be massless higher spin fields. With my poster, we discuss whether the unitary symmetry of the matrices includes appropriate higher spin gauge symmetries. We find that the additional...

46. How information geometry is encoded in bulk geometry

Mr Kazushi Yamashiro

05/12/2019, 15:00

We study how information geometry is described by bulk geometry in the gauge/gravity correspondence. We consider a quantum information metric that measures the distance between the ground states of a CFT and a theory obtained by perturbing the CFT. Using the GKP-Witten relation, we find a universal formula that expresses the quantum information metric by a geometrical quantity in a...

36. Infrared renormalon in the supersymmetric $\mathbb{C}P^{N-1}$ model on $\mathbb{R}\times S^1$

Mr Okuto Morikawa

05/12/2019, 15:00

In the leading order of the large $N$ approximation, we study the renormalon ambiguity in the gluon (or more appropriately, photon) condensate in the two-dimensional supersymmetric $\mathbb{C}P^{N-1}$ model on $\mathbb{R}\times S^1$ with the $\mathbb{Z}_N$ twisted boundary conditions. In our large $N$ limit, the combination $\Lambda R$, where $\Lambda$ is the dynamical scale and $R$ is the...

43. Instability of Higgs Vacuum via String Cloud

Mr Issei Koga

05/12/2019, 15:00

We study the instability of the Higgs vacuum caused by a cloud of strings. By the catalysis, the decay rate of the vacuum is highly enhanced and when the energy density of the cloud is larger than the critical value, the semi-classical vacuum decay occurs. We also discuss the relation between the cloud of strings and observational constraints on cosmic strings in terms of the catalysis,...

55. Localization of gauge field on 3-branes and Higgs mechanism

Mr Masaki Kawaguchi

05/12/2019, 15:00

We provide complete and self-contained formulas about localization of massless/massive Abelian gauge fields on topological solitons in generic D dimensions via a field dependent gauge kinetic term. The localization takes place when a stabilizer (a scalar field) is condensed in the topological soliton. We show that the localized gauge bosons are massless when the stabilizer is neutral. On the...

48. On UV-finiteness of supersymmetric gradient flow in N=1 SQCD

Mr Mitsuyo Suzuki

05/12/2019, 15:00

I will discuss perturbation theory of supersymmetric gradient flow in 4D N = 1 SQCD. The perturbation theory consists of a perturbative expansion of 4D SQCD and an iterative expansion of the flow equation. In order to prove UV-finiteness of flow theory, it is necessary to calculate its correlation functions and to construct a d+1-dimensional theory which reproduces the same perturbation series.

37. Sign flip triangulation of the 1-loop NMHV amplituhedron

Mr Ryota Kojima

05/12/2019, 15:00

In this talk, I will talk about the triangulation of the amplituhedron. To obtain higher point amplitude from the general amplituhedron, we need to triangulate it into a simple one. There is some way to triangulate the amplituhedron and some of this gives new representations of the amplitude. I will briefly explain the amplituhedron and its property, then I will talk about the new...

44. Superconformal index and supersymmetry enhancement of S-fold theories

Mr Reona Arai

05/12/2019, 15:00

Recently concrete models of 4d N=3 superconformal field theories called S-fold theories are constructed by Garcia-Etxebarria and Regalado. Although it is difficult to study these theories due to the lack of the Lagrangian description and the strong coupling, it is expected that there is a non-trivial supersymmetry enhancement for rank one and two theories by Aharony and Tachikawa. In this...

53. Tricritical point and non-equilibrium phase transition in gauge gravity duality

Mr Masataka Matsumoto

05/12/2019, 15:00

We study the phase structure associated with the chiral symmetry in the D3-D7 model. We find the non-equilibrium phase transition for massless quarks in the presence of a constant current and a magnetic field. This non-equilibrium phase transition is related to the chiral symmetry breaking. We also discover the tricritical point in the phase diagram.

52. TT-bar deformation in large N limit

Mr Junichi Haruna

05/12/2019, 15:00

We consider two dimensional TT-bar deformed O(N) invariant massive scalar theory in large N limit, and investigate its renormalizability at 1/N ( next to leading ) level. As a result, we find that we need to renormalize the deformation parameter at leading level, and non-local counterterms at 1/N (next to leading) level. Also we find that positivity of state space is violated in the UV region...

61. Unitary matrix model with the logarithmic potential

Mr Hitomi TASHIRO (SOKENDAI)

05/12/2019, 15:00

We study the unitary one-matrix model with the logarithmic potential. It has been known that a hermitian one-matrix model with a logarithmic potential yields the prepotential of 4d N=2 SU(2) SUSY gauge theory as its large-N free energy. We give a rigorous proof that the unitary matrix model with the potential of the same form as the hermitian matrix model for 4d N=2 Nf=2 SU(2) SUSY gauge...