Hikaru Uchida

activity

20182026

most citedFinite modular subgroups for fermion mass matrices and baryon/lepton number violation

159 citations · 780 across the 34 of their papers we have counts for

collaborators

34 papers

hep-th2026

Massive modes on magnetized blow-up manifold of $T^{2} / Z_{N}$

Tatsuo Kobayashi, Hajime Otsuka, Hikaru Uchida

We study massive modes on a magnetized blow-up manifold of $T^{2} / Z_{N}$ . The blow-up manifold can be constructed by appropriately replacing orbifold singular points with a pa…

hep-th2025

Modular weights of wave functions on magnetized torus

Tim Jeric, Tatsuo Kobayashi, Hajime Otsuka +2

We study the origin of modular weights of wave functions in magnetized $T^{2}$ models. It is explicitly demonstrated that the modular weights of the wave functions on magnetized $T…

hep-th2024

Modular symmetry of localized modes

Tatsuo Kobayashi, Hajime Otsuka, Shohei Takada +1

We study the modular symmetry of localized modes on fixed points of $T^{2} / Z_{2}$ orbifold. First, we find that the localized modes with even (odd) modular weight generally ha…

hep-ph2023

$S p (6, Z)$ modular symmetry in flavor structures: quark flavor models and Siegel modular forms for $Δ (96)$

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +2

We study an approach to construct Siegel modular forms from $S p (6, Z)$ . Zero-mode wave functions on $T^{6}$ with magnetic flux background behave Siegel modular forms at the origin. Th…

hep-th2023

Modular symmetry in magnetized $T^{2 g}$ torus and orbifold models

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +2

We study the modular symmetry in magnetized $T^{2 g}$ torus and orbifold models. The $T^{2 g}$ torus has the modular symmetry $Γ_{g} = S p (2 g, Z)$ . Magnetic flux background brea…

hep-th2023★ 7 cited

Zero-modes in magnetized $T^{6} / Z_{N}$ orbifold models through $S p (6, Z)$ modular symmetry

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +2

We study of fermion zero-modes on magnetized $T^{6} / Z_{N}$ orbifolds. In particular, we focus on non-factorizable orbifolds, i.e. $T^{6} / Z_{7}$ and $T^{6} / Z_{12}$ …

hep-th2023

Flavor structure in magnetized orbifold and blow-up manifold compactification

Hikaru Uchida

As the effective field theory of the superstring theory, ten-dimensional $N = 1$ supersymmetric Yang-Mills theory is induced. We consider the ten-dimensional space-time ${\cal…

hep-th2023★ 2 cited

Three-generation solutions of equations of motion in heterotic supergravity

Maki Takeuchi, Takanao Tsuyuki, Hikaru Uchida

We study the generation number of massless fermions in compactifications recently found in heterotic supergravity. The internal spaces are products of two-dimensional spaces of con…

hep-ph2023★ 26 cited

Quark mass hierarchies and CP violation in $A_{4} \times A_{4} \times A_{4}$ modular symmetric flavor models

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +2

We study $A_{4} \times A_{4} \times A_{4}$ modular symmetric flavor models to realize quark mass hierarchies and mixing angles without fine-tuning. Mass matrices are written in terms of…

hep-ph2023★ 28 cited

Quark hierarchical structures in modular symmetric flavor models at level 6

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +2

We study modular symmetric quark flavor models without fine-tuning. Mass matrices are written in terms of modular forms, and modular forms in the vicinity of the modular fixed poin…

hep-th2023★ 11 cited

Remark on modular weights in low-energy effective field theory from type II string theory

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +3

We revisit the modular weights in type IIB magnetized D-brane models. The simple analysis of wave function shows that the four-dimensional matter fields have the modular weight -1/…

hep-th2022★ 2 cited

Zero-mode wave functions by localized gauge fluxes

Tatsuo Kobayashi, Hajime Otsuka, Makoto Sakamoto +3

We study chiral zero-mode wave functions on blow-up manifolds of $T^{2} / Z_{N}$ orbifolds with both bulk and localized magnetic flux backgrounds. We introduce a singular gauge transform…

hep-th2022★ 12 cited

Index theorem on magnetized blow-up manifold of $T^{2} / Z_{N}$

Tatsuo Kobayashi, Hajime Otsuka, Makoto Sakamoto +3

We investigate blow-up manifolds of $T^{2} / Z_{N} (N = 2, 3, 4, 6)$ orbifolds with magnetic flux $M$ . Since the blow-up manifolds have no singularities, we can apply the Atiyah-S…

hep-th2022★ 10 cited

Number of zero-modes on magnetized $T^{4} / Z_{N}$ orbifolds analyzed by modular transformation

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +2

We study fermion zero-mode wavefunctions on $T^{4} / Z_{N}$ orbifold with background magnetic fluxes. The number of zero-modes is analyzed by use of $S p (4, Z)$ modular transforma…

hep-ph2022★ 20 cited

Quark and lepton flavor structure in magnetized orbifold models at residual modular symmetric points

Kouki Hoshiya, Shota Kikuchi, Tatsuo Kobayashi +1

We study quark and lepton mass matrices derived from magnetized $T^{2} / Z_{2}$ orbifold models. Quark and lepton masses have a large hierarchy. In addition, mixing angles are l…

hep-ph2022★ 17 cited

Texture zeros of quark mass matrices at fixed point $τ = ω$ in modular flavor symmetry

Shota Kikuchi, Tatsuo Kobayashi, Morimitsu Tanimoto +1

We study systematically derivation of the specific texture zeros, that is the nearest neighbor interaction (NNI) form of the quark mass matrices at the fixed point $τ = ω$ in modular…

hep-ph2022★ 1 cited

Mass matrices with CP phase in modular flavor symmetry

Shota Kikuchi, Tatsuo Kobayashi, Morimitsu Tanimoto +1

We study the CP violation and the CP phase of quark mass matrices in modular flavor symmetric models. The CP symmetry remains at $τ = e^{2 π i /3}$ by a combination of the $T$ -symmetr…

hep-ph2022★ 2 cited

Modular symmetry of soft supersymmetry breaking terms

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +3

We study the modular symmetry of soft supersymmetry breaking terms. Soft scalar masses and $A$ -term coefficients are invariant under the modular symmetry when we regard $F$ -term as…

hep-th2022★ 12 cited

Classifications of magnetized $T^{4}$ and $T^{4} / Z_{2}$ orbifold models

Shota Kikuchi, Tatsuo Kobayashi, Kaito Nasu +1

We study constructions and classifications of three-generation models based on magnetized $T^{4}$ and $T^{4} / Z_{2}$ orbifold as candidates of the compact space. We focus on chiral ferm…

hep-th2022★ 9 cited

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…

hep-ph2022★ 14 cited

4D modular flavor symmetric models inspired by higher dimensional theory

Shota Kikuchi, Tatsuo Kobayashi, Hajime Otsuka +3

We study a scenario to derive four-dimensional modular flavor symmetric models from higher dimensional theory by assuming the compactification consistent with the modular symmetry.…

hep-ph2021

Yukawa textures in modular symmetric vacuum of magnetized orbifold models

Shota Kikuchi, Tatsuo Kobayashi, Yuya Ogawa +1

We study quark mass matrices derived from magnetized $T^{2} / Z_{2}$ orbifold models. Yukawa matrices at three modular fixed points, $τ = i, e^{2 π i /3}$ and $i \infty$ are invariant…

hep-th2021★ 10 cited

Anomaly of non-Abelian discrete symmetries

Tatsuo Kobayashi, Hikaru Uchida

We study anomalies of non-Abelian discrete symmetries; which part of non-Abelian group is anomaly free and which part can be anomalous. It is found that the anomaly-free elements o…

hep-th2021★ 3 cited

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…

Massive modes on magnetized blow-up manifold of T2/ZN​

Modular weights of wave functions on magnetized torus

Modular symmetry of localized modes

Sp(6,Z) modular symmetry in flavor structures: quark flavor models and Siegel modular forms for Δ(96)

Modular symmetry in magnetized T2g torus and orbifold models

Zero-modes in magnetized T6/ZN​ orbifold models through Sp(6,Z) modular symmetry

Flavor structure in magnetized orbifold and blow-up manifold compactification

Three-generation solutions of equations of motion in heterotic supergravity

Quark mass hierarchies and CP violation in A4​×A4​×A4​ modular symmetric flavor models

Quark hierarchical structures in modular symmetric flavor models at level 6

Remark on modular weights in low-energy effective field theory from type II string theory

Zero-mode wave functions by localized gauge fluxes

Index theorem on magnetized blow-up manifold of T2/ZN​

Number of zero-modes on magnetized T4/ZN​ orbifolds analyzed by modular transformation

Quark and lepton flavor structure in magnetized orbifold models at residual modular symmetric points

Texture zeros of quark mass matrices at fixed point τ=ω in modular flavor symmetry

Mass matrices with CP phase in modular flavor symmetry

Modular symmetry of soft supersymmetry breaking terms

Classifications of magnetized T4 and T4/Z2​ orbifold models

Modular symmetry anomaly and non-perturbative neutrino mass terms in magnetized orbifold models

4D modular flavor symmetric models inspired by higher dimensional theory

Yukawa textures in modular symmetric vacuum of magnetized orbifold models

Anomaly of non-Abelian discrete symmetries

Majorana neutrino masses by D-brane instanton effects in magnetized orbifold models

Massive modes on magnetized blow-up manifold of $T^{2} / Z_{N}$

$S p (6, Z)$ modular symmetry in flavor structures: quark flavor models and Siegel modular forms for $Δ (96)$

Modular symmetry in magnetized $T^{2 g}$ torus and orbifold models

Zero-modes in magnetized $T^{6} / Z_{N}$ orbifold models through $S p (6, Z)$ modular symmetry

Quark mass hierarchies and CP violation in $A_{4} \times A_{4} \times A_{4}$ modular symmetric flavor models

Index theorem on magnetized blow-up manifold of $T^{2} / Z_{N}$

Number of zero-modes on magnetized $T^{4} / Z_{N}$ orbifolds analyzed by modular transformation

Texture zeros of quark mass matrices at fixed point $τ = ω$ in modular flavor symmetry

Classifications of magnetized $T^{4}$ and $T^{4} / Z_{2}$ orbifold models