22 citations · 86 across the 13 of their papers we have counts for
13 papers
A new picture of quantum tunneling in the real-time path integral from Lefschetz thimble calculations
Jun Nishimura, Katsuta Sakai, Atis Yosprakob
It is well known that quantum tunneling can be described by instantons in the imaginary-time path integral formalism. However, its description in the real-time path integral formal…
Backpropagating Hybrid Monte Carlo algorithm for fast Lefschetz thimble calculations
Genki Fujisawa, Jun Nishimura, Katsuta Sakai +1
The Picard-Lefschetz theory has been attracting much attention as a tool to evaluate a multi-variable integral with a complex weight, which appears in various important problems in…
Non-Gaussianity of Entanglement Entropy and Correlations of Composite Operators
Satoshi Iso, Takato Mori, Katsuta Sakai
This is an extended version of the previous paper arXiv:2103.05303 to study entanglement entropy (EE) of a half space in interacting field theories. In the previous paper, we have…
Wilsonian Effective Action and Entanglement Entropy
Satoshi Iso, Takato Mori, Katsuta Sakai
This is a continuation of our previous works on entanglement entropy (EE) in interacting field theories. In arXiv:2103.05303, we have proposed the notion of gauge th…
Burgers Equation vs. Large Limit in -deformed Vector Model
Junichi Haruna, Katsuta Sakai, Kentaroh Yoshida
We study a -deformed vector model, which is classically equivalent to the Nambu-Goto action with static gauge. The thermal free energy density can be computed exac…
Entanglement entropy in scalar field theory and gauge theory on Feynman diagrams
Satoshi Iso, Takato Mori, Katsuta Sakai
Entanglement entropy (EE) in interacting field theories has two important issues: renormalization of UV divergences and non-Gaussianity of the vacuum. In this letter, we investigat…
Large N Analysis of -deformation and Unavoidable Negative-norm States
Junichi Haruna, Takaaki Ishii, Hikaru Kawai +2
We study non-perturbative quantum aspects of -deformation of a free vector model by employing the large limit. It is shown that bound states of the original fi…
A note on higher spin symmetry in the IIB matrix model with the operator interpretation
Katsuta Sakai
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 deriva…
A novel regularization of chiral gauge theory
Yu Hamada, Hikaru Kawai, Katsuta Sakai
We propose a novel gauge-invariant regularization for the perturbative chiral gauge theory.Our method consists of the two ingredients: use of the domain-wall fermion to describe a…
Hillclimbing saddle point inflation
Kiyoharu Kawana, Katsuta Sakai
Recently a new inflationary scenario was proposed in arXiv:1703.09020 which can be applicable to an inflaton having multiple vacua. In this letter, we consider a more general situa…
Stability of the Matrix Model in Operator Interpretation
Katsuta Sakai
The IIB matrix model is one of the candidates for nonperturbative formulation of string theory, and it is believed that the model contains gravitational degrees of freedom in some…
A note on graviton exchange in emergent gravity scenario
Hikaru Kawai, Kiyoharu Kawana, Katsuta Sakai
It is well-known that there exists a close relation between a large matrix model and noncommutative (NC) field theory: The latter can be naturally obtained from the former by e…
Massive higher spin fields in curved spacetime and necessity of non-minimal couplings
Masafumi Fukuma, Hikaru Kawai, Katsuta Sakai +1
Free massive higher spin fields in weak background gravitational fields are discussed. Contrary to the spin one case, higher spin fields should have nontrivial non-minimal coupling…