226 citations · 1.4k across the 19 of their papers we have counts for
19 papers
Revisiting modular symmetry in magnetized torus and orbifold compactifications
Shota Kikuchi, Tatsuo Kobayashi, Shintaro Takada +2
We study the modular symmetry in and orbifold comfactifications with magnetic fluxes. There are zero-modes on with the magnetic flux . Their wavefunctions as w…
violation in modular invariant flavor models
Tatsuo Kobayashi, Yusuke Shimizu, Kenta Takagi +3
We study the spontaneous violation through the stabilization of the modulus in modular invariant flavor models. The -invaraiant potentential has the minimum only at ${…
Modular invariance and leptogenesis
Takehiko Asaka, Yongtae Heo, Takuya H. Tatsuishi +1
We consider a model with three right-handed neutrinos in which Yukawa coupling constants and Majorana masses are obtained by requiring the modular symmetry. It has been shown…
lepton flavor model and modulus stabilization from modular symmetry
Tatsuo Kobayashi, Yusuke Shimizu, Kenta Takagi +2
We study the modulus stabilization in an model whose flavor symmetry is originated from the modular symmetry. We can stabilize the modulus so that the invar…
New lepton flavor model from modular symmetry
Tatsuo Kobayashi, Yusuke Shimizu, Kenta Takagi +2
We study a flavor model with symmetry which originates from modular group. In symmetry, subgroup can be anomalous, and then can be violated to .…
Modular invariant flavor model in SU(5) GUT
Tatsuo Kobayashi, Yusuke Shimizu, Kenta Takagi +2
We present a flavor model with the modular invariance in the framework of SU(5) GUT. The modular forms of weights and give the quark and lepton mass matrices wi…
On Experimental Confirmation of the Corrections to the Fermi's golden rule
Kenzo Ishikawa, Osamu Jinnouchi, Arisa Kubota +3
Standards calculations by the Fermi's Golden rule involve approximations. These approximations could lead to deviations from the predictions of the standard model as discussed in a…
Finite modular subgroups for fermion mass matrices and baryon/lepton number violation
Tatsuo Kobayashi, Yusuke Shimizu, Kenta Takagi +3
We study a flavor model that the quark sector has the modular symmetry,while the lepton sector has the modular symmetry. Our model leads to characteristic quark mass ma…
F-term Moduli Stabilization and Uplifting
Tatsuo Kobayashi, Osamu Seto, Shintaro Takada +3
We study Kähler moduli stabilization in IIB superstring theory. We propose a new moduli stabilization mechanism by the supersymmetry-braking chiral superfield which is coupled to K…
Modular invariance and neutrino mixing
Tatsuo Kobayashi, Naoya Omoto, Yusuke Shimizu +3
We study the phenomenological implications of the modular symmetry of lepton flavors facing recent experimental data of neutrino oscillations. The mass matrices o…
Quark mass matrices in magnetized orbifold models with localized Fayet-Iliopoulos terms
H. Abe, T. Kobayashi, S. Takada +2
We study magnetized orbifold models. We assume the localized Fayet-Iliopoulos terms and the corresponding gauge background. Such terms lead to strong localization of zero-mode wave…
Modular symmetry and non-Abelian discrete flavor symmetries in string compactification
Tatsuo Kobayashi, Satoshi Nagamoto, Shintaro Takada +2
We study the modular symmetry in magnetized D-brane models on . Non-Abelian flavor symmetry in the model with magnetic flux (in a certain unit) is a subgroup of th…
Neutrino mixing from finite modular groups
Tatsuo Kobayashi, Kentaro Tanaka, Takuya H. Tatsuishi
We study the lepton flavor models, whose flavor symmetries are finite subgroups of the modular group such as and . In our models, couplings are also nontrivial represent…
Radiative Kähler moduli stabilization
Tatsuo Kobayashi, Naoya Omoto, Hajime Otsuka +1
We propose a new type of Kähler moduli stabilization mechanisms in type IIB superstring theory on Calabi-Yau manifolds with the positive Euler number. The overall Kähler modulus ca…
Supersymmetry preserving and breaking degenerate vacua, and radiative moduli stabilization
Tatsuo Kobayashi, Naoya Omoto, Hajime Otsuka +1
We propose a new type of moduli stabilization scenario where the supersymmetric and supersymmetry-breaking minima are degenerate at the leading level. The inclusion of the loop-cor…
Toward pole inflation and attractors in supergravity : Chiral matter field inflation
Tatsuo Kobayashi, Osamu Seto, Takuya H. Tatsuishi
In string-inspired supergravity theory, Kähler metric of chiral matter fields often has a pole. Such Kähler metric is interesting from the viewpoint of the framework of the pole in…
Small field axion inflation with sub-Planckian decay constant
Kenji Kadota, Tatsuo Kobayashi, Akane Oikawa +3
We study an axion inflation model recently proposed within the framework of type IIB superstring theory, where we pay a particular attention to a sub-Planckian axion decay constant…
Flavor structure in heterotic string theory
Hiroyuki Abe, Tatsuo Kobayashi, Hajime Otsuka +2
We study the flavor structure in heterotic string theory on six-dimensional torus with magnetic fluxes. In particular, we focus on models with the flavor symmetries $SU(3)…
Gauge coupling unification in SO(32) heterotic string theory with magnetic fluxes
Hiroyuki Abe, Tatsuo Kobayashi, Hajime Otsuka +2
We study heterotic string theory on torus with magnetic fluxes. Non-vanishing fluxes can lead to non-universal gauge kinetic functions for $SU(3) \times SU(2) \times U(1)_…