101 citations · 274 across the 14 of their papers we have counts for
14 papers
Modular symmetry anomaly and non-perturbative neutrino mass terms in magnetized orbifold models
Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +2
We study the modular symmetry anomaly in magnetized orbifold models. The non-perturbative effects such as D-brane instanton effects can break tree-level symmetry. We study which pa…
Modular Origin of Mass Hierarchy: Froggatt-Nielsen like Mechanism
Hitomi Kuranaga, Hiroshi Ohki, Shohei Uemura
We study Froggatt-Nielsen (FN) like flavor models with modular symmetry. The FN mechanism is a convincing solution to the flavor puzzle in quark sector. The FN mechanism requires a…
Majorana neutrino masses by D-brane instanton effects in magnetized orbifold models
Kouki Hoshiya, Shota Kikuchi, Tatsuo Kobayashi +3
We study Majorana neutrino masses induced by D-brane instanton effects in magnetized orbifold models. We classify possible cases, where neutrino masses can be induced. Three and fo…
Modular Flavor Symmetry on Magnetized Torus
Hiroshi Ohki, Shohei Uemura, Risa Watanabe
We study the modular invariance in magnetized torus models. Modular invariant flavor model is a recently proposed hypothesis for solving the flavor puzzle, where the flavor symmetr…
Loop Fayet-Iliopoulos terms in models: instability and moduli stabilization
Hiroyuki Abe, Tatsuo Kobayashi, Shohei Uemura +1
We study Fayet-Iliopoulos (FI) terms of six-dimensional supersymmetric Abelian gauge theory compactified on a orbifold. Such orbifold compactifications can lead to locali…
Revisiting instabilities of models with loop-induced Fayet-Iliopoulos terms
Hiroyuki Abe, Tatsuo Kobayashi, Shohei Uemura +1
We study Fayet-Iliopoulos (FI) terms of 5-dimensional supersymmetric gauge theory compactified on . In this model, loop diagrams including matter hypermultiplets an…
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…
Poly-instanton axion inflation
Tatsuo Kobayashi, Shohei Uemura, Junji Yamamoto
We investigate the axion inflation model derived by poly-instanton effects in type II superstring theories. Poly-instanton effects are instanton effects corrected by another instan…
Kähler moduli stabilization in semi-realistic magnetized orbifold models
Hiroyuki Abe, Tatsuo Kobayashi, Keigo Sumita +1
We study Kähler moduli stabilizations in semi-realistic magnetized D-brane models based on toroidal orbifolds. In type IIB compactifications, 3-form fluxes can st…
Modular symmetry in magnetized/intersecting D-brane models
Tatsuo Kobayashi, Satoshi Nagamoto, Shohei Uemura
We study the modular symmetry in four-dimensional low-energy effective field theory, which is derived from type IIB magnetized D-brane models and type IIA intersecting D-brane mode…
Majorana neutrino mass structure induced by rigid instatons on toroidal orbifold
Tatsuo Kobayashi, Yoshiyuki Tatsuta, Shohei Uemura
We study effects of D-brane instantons wrapping rigid cycles on Z2*Z2' toroidal orbifold. We compute Majorana masses induced by rigid D-brane instantons and realize bimaximal mixin…
D-brane instanton induced mu-terms and their hierarchical structure
Hiroyuki Abe, Tatsuo Kobayashi, Yoshiyuki Tatsuta +1
We study the mu-term matrix of Higgs pairs induced by the D-brane instanton effects in intersecting D6-brane models compactified on T6. It is found that the mu-term matrix has a ce…
Standard Model-like D-brane models and gauge couplings
Yuta Hamada, Tatsuo Kobayashi, Shohei Uemura
We systematically search intersecting D-brane models, which just realize the Standard Model chiral matter contents and gauge symmetry. We construct new classes of non-supersymmetri…
Flavor structure in D-brane models: Majorana neutrino masses
Yuta Hamada, Tatsuo Kobayashi, Shohei Uemura
We study the flavor structure in intersecting D-brane models. We study anomalies of the discrete flavor symmetries. We analyze the Majorana neutrino masses, which can be generated…