Publishing type：Research paper (scientific journal)  

We study primordial electromagnetic fields in effective actions of string theory. In contrast to a conventional scenario of producing primordial electromagnetic fields induced by the axion inflation, we deal with the Dirac-Born-Infeld action as a non-linear generation of Maxwell theory. It turns out that the intensity of generated electromagnetic fields is bounded from above by the string scale which can also be rewritten in terms of supersymmetry breaking scale in the context of type IIB Large Volume Scenario. The instability parameter ξ is constrained by the tadpole cancellation condition of D3-branes and a realization of hierarchy between the string scale and the Hubble scale of inflation. Hence, the magnetogenesis can be realized in the limited corner of the string landscape due to the O(1) value of the coefficient of Chern-Simons coupling.

DOI： 10.1007/JHEP07(2024)055

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Publishing type：Research paper (scientific journal)  

We derive verifiable two-zero textures in the framework of a three-loop induced neutrino mass model applying a modular A4 symmetry for the lepton sector. Interestingly, the neutrino mass structure is determined by assignments of the right-handed charged-lepton particles only. We show all the possible texture patterns and demonstrate their analytical and numerical analyses. Finally, we mention a possibility of detection for doubly-charged boson via colliders that decays into specific modes due to the flavor symmetry.

DOI： 10.1016/j.nuclphysb.2024.116579

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Publishing type：Research paper (scientific journal)  

We investigate the cosmological expansion of the 3D space in a 6D model compactified on a sphere, beyond the 4D effective theory analysis. We focus on a case where the initial temperature is higher than the compactification scale. In such a case, the pressure for the compact space affects the moduli dynamics and induces the moduli oscillation even if they are stabilized at the initial time. Under some plausible assumptions, we derive the explicit expressions for the 3D scale factor and the moduli background in terms of analytic functions. Using them, we evaluate the transition times between different cosmological eras as functions of the model parameters and the initial temperature.

DOI： 10.1103/PhysRevD.109.115019

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We study structures of solutions for SUSY Minkowski F-term equations on two toroidal orientifolds with h2,1 = 1. Following our previous study [1], with fixed upper bounds of a flux D3-brane charge Nflux, we obtain a whole Landscape and a distribution of degeneracies of physically-distinct solutions for each case. In contrast to our previous study, we consider a non-factorizable toroidal orientifold and its Landscape on which SL(2, ℤ) is violated into a certain congruence subgroup, as it had been known in past studies. We find that it is not the entire duality group that a complex-structure modulus U enjoys but its outer semi-direct product with a “scaling” outer automorphism group. The fundamental region is enlarged to include the |U| < 1 region. In addition, we find that high degeneracy is observed at an elliptic point, not of SL(2, Z) but of the outer automorphism group. Furthermore, ℤ2-enhanced symmetry is realized on the elliptic point. The outer automorphism group is exceptional in the sense that it is consistent with a symplectic basis transformation of background three-cycles, as opposed to the outer automorphism group of SL(2, ℤ). We also compare this result with Landscape of another factorizable toroidal orientifold.

DOI： 10.1007/JHEP02(2024)099

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We propose an upper bound on the Atiyah-Singer index in the effective action of string theory. For E 8 × E8′ and SO(32) heterotic string theories on smooth Calabi-Yau threefolds with line bundles, we find that the tadpole cancellation and supersymmetry conditions lead to an upper bound on the generation number of quarks and leptons as well as Higgs doublets. By taking into account the observed value of four-dimensional gauge couplings and the supergravity approximation, we explicitly evaluate the bound on favorable complete intersection Calabi-Yau threefolds. The bound can be extended to Calabi-Yau threefolds in the Kreuzer-Skarke database. We also put the upper bound on the Atiyah-Singer index in Type IIB/F-theory compactifications.

DOI： 10.1007/JHEP01(2024)200

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Sequestering is a promising mechanism in 4D string models to reconcile high-scale inflation with low-energy supersymmetry. In this scenario the MSSM lives on branes at singularities and it is sequestered from the sources of supersymmetry breaking in the bulk. The soft-terms are suppressed with respect to the gravitino mass so that all moduli are heavy enough to avoid any cosmological moduli problem. In this paper we study stability bounds and flavour constraints on sequestered string models, finding that they can be satisfied if the soft-terms give rise to a mass spectrum typical of split supersymmetry with TeV-scale gauginos and sfermions around 107 GeV. When instead scalar and gaugino masses are of the same order of magnitude, large flavour changing neutral currents can be avoided only by pushing the soft-terms above 106 GeV. However this scenario is in tension with stability bounds due to the presence of charge and colour breaking vacua which could be populated in the early universe, and the possible emergence of directions along which the potential is unbounded from below.

DOI： 10.1007/JHEP01(2024)059

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We propose an interesting assignment of positive modular weights for fields in a modular non-Abelian discrete flavor symmetry. By this assignment, we can construct inverse seesaw and linear seesaw models without any additional symmetries which possess good testability in current experiments. At first, we discuss possibilities for positive modular weights from a theoretical point of view. Then we show concrete examples of inverse seesaw and linear seesaw scenarios applying modular A 4 symmetry as examples and demonstrate some predictions as well as consistency with experimental results such as neutrino masses and mixings.

DOI： 10.1007/JHEP01(2024)121

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Language：Japanese   Publisher：The Japanese Society for Artificial Intelligence  

<p>In theoretical particle physics, various hypothetical models are proposed to explain unsolved problems of particle phenomena. To validate them exhaustively, theoretical predictions should be compared with experimental data. However, the parameter space is large in general, so it is difficult to analyze the models numerically with low cost. In this work considering such a situation, we focus on matter particles that are called as quarks and leptons, and improve a method to explore their flavor structure with reinforcement learning. We utilize Deep Q-Network for one kind of the models, and train neural networks on the integer charges of quarks and leptons. The results show that there are indeed solutions that reproduce the experimental and renormalized masses of the quarks and leptons. On the other hand, the results suggest that appropriate parameters are very scarce when considering domain-wall problems, which are severely constrained by cosmological observations. Given its usefulness for such analysis, we expect that reinforcement learning can be applied to the verification of realistic particle models.</p>

DOI： 10.11517/pjsai.jsai2024.0_1f4gs1003

CiNii Research

Language：Others   Publishing type：Research paper (scientific journal)  

We propose a method to explore the flavor structure of quarks and leptons with reinforcement learning. As a concrete model, we utilize a basic value-based algorithm for models with U(1) flavor symmetry. By training neural networks on the U(1) charges of quarks and leptons, the agent finds 21 models to be consistent with experimentally measured masses and mixing angles of quarks and leptons. In particular, an intrinsic value of normal ordering tends to be larger than that of inverted ordering, and the normal ordering is well fitted with the current experimental data in contrast to the inverted ordering. A specific value of effective mass for the neutrinoless double beta decay and a sizable leptonic CP violation induced by an angular component of flavon field are predicted by autonomous behavior of the agent. Our finding results indicate that the reinforcement learning can be a new method for understanding the flavor structure.

DOI： 10.1007/JHEP12(2023)021

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We examine symmetries of chiral four-dimensional vacua of Type IIB flux compactifications with vanishing superpotential W = 0. We find that the N = 1 supersymmetric MSSM-like and Pati-Salam vacua possess enhanced discrete symmetries in the effective action below the mass scale of stabilized complex structure moduli and dilaton. Furthermore, a generation number of quarks/leptons is small on these vacua where the flavor, CP and metaplectic modular symmetries are described in the framework of eclectic flavor symmetry.

DOI： 10.1007/JHEP12(2023)136

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

We study slow-roll inflation model controlled by the modular flavor symmetry.
In the model, the modulus field plays a role of inflaton and the introduction
of the stabilizer field coupled to a modular form in the superpotential
produces the inflaton potential. In order to generate the flat direction for
the slow-roll inflation, we consider the K\"{a}hler potential corrected by the
modular form. It is noted that the modulus field perpendicular to the inflaton
direction is stabilized during the inflation. The model is turns out to be
consistent with the current observations and behaves similarly to the
$\alpha$-attractor models in some parameter spaces. The inflaton rolls down to
the CP-symmetric vacuum at the end of inflation.

DOI： 10.1007/JHEP06(2023)187

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arXiv

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Other Link： http://arxiv.org/pdf/2303.02947v1

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

We investigate effects of the radiation and the moduli oscillation around the
stabilized values on the evolution of a 6-dimensional spacetime compactified on
$S^2$. In order to see the transition from the 5-dimensional space to the
3-dimensional one, we develop a procedure to pursue the spacetime evolution
with appropriate approximations, which is valid until the spacetime behaves
like 4-dimensional. In the case that the moduli stabilization process cannot be
described in the context of the 4-dimensional effective theory, it takes quite
a long time for the moduli oscillation to dominate the total energy density, in
contrast to the conventional result obtained by the 4-dimensional effective
theory approach. We also found that even if the moduli are set at the
stabilized values, they start to oscillate due to the pressure in the extra
space $S^2$ in some cases.

DOI： 10.1007/JHEP05(2023)231

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arXiv

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Other Link： http://arxiv.org/pdf/2212.14314v1

Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS INC  

We classify a supersymmetric extension of the Standard Model by discrete symmetries originating from finite modular symmetries Gamma(N). Since all the couplings in supersymmetric theories of finite modular symmetries Gamma(N) are described by holomorphic modular forms with even modular weights, renormalizable and non-renormalizable operators such as baryon- and/or lepton-number violating operators are severely constrained. From the modular transformation of matter multiplets with modular weight 1/M, we find Z(2M) symmetries, including the generalized baryon and lepton parities, R-parity, Z(3) baryon triality and Z(6) proton hexality. Such Z(2M) symmetries are enlarged to Z(2M) (sic) Z(2)(CP) symmetries together with the CP transformation.

DOI： 10.1093/ptep/ptad041

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER PHYSICAL SOC  

We investigate blow-up manifolds of T2=7LN(N = 2; 3; 4; 6) orbifolds with magnetic flux. First, we construct the blow-up manifolds and zero-mode wave functions on them more precisely. In particular, through an appropriate singular gauge transformation, winding numbers of wave functions on T2=7LN can be replaced with localized curvature and localized flux at orbifold fixed points. In addition, since the blow-up manifolds have no singularities, we apply the Atiyah-Singer index theorem to them; the chiral zero-mode number is given by the total magnetic flux. It can be also applied for T2=7LN orbifolds through the blow-up process, and then we find that it is consistent with the zero-mode counting formula in M. Sakamoto et al. [Zero-mode counting formula and zeros in orbifold compactifications, Phys. Rev. D 102, 025008 (2020).]. Furthermore, the Atiyah-Singer index theorem shows that an additional degree of freedom of localized flux gives new chiral zero modes. We study their wave functions and then we find that they correspond to localized modes at the orbifold singular points. We also calculate their Yukawa couplings.

DOI： 10.1103/PhysRevD.107.075032

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Language：Others   Publishing type：Research paper (scientific journal)  

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 -1/2, but it may shift as one in type IIA intersecting D-brane models. For example, the localized gauge flux as well as the localized curvature can shift the modular weight in the magnetized D-brane models. Such corrections do not affect physical couplings such as physical Yukawa couplings. However, it leads to differences in supersymmetry breaking sfermion masses, which depend on the modular weights, although the A-term coefficients and the sum of sfermion masses squared seem to be the same between two models.

DOI： 10.1007/JHEP04(2023)003

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Language：Others   Publishing type：Research paper (scientific journal)  

We apply the Festina Lente (FL) bound on a hidden sector with $U(1)$ gauge
symmetries. Since the FL bound puts a lower bound on masses of particles
charged under the $U(1)$ gauge symmetries, it is possible to constrain the
hidden sector even with a tiny coupling to the Standard Model. In particular,
we focus on the phenomenological implications of the FL bound on milli-charged
particles, which naturally arise when kinetic mixing between the photon and the
hidden photon is allowed. It turns out that the milli-charged particle with the
mass $M\lesssim 5$ meV is prohibited by the FL bound in the case of a single
hidden $U(1)$, independent of the value of kinetic mixing. This bound is
crucial when bosonic dark matter is taken in consideration in this framework:
the fuzzy bosonic dark matter models requesting minuscule masses are ruled out
by the FL bound if the longevity of dark matter is protected by the hidden
gauge symmetry.

DOI： 10.1093/ptep/ptac176

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arXiv

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Other Link： http://arxiv.org/pdf/2206.00890v1

Language：Others   Publishing type：Research paper (scientific journal)  

We propose a pseudo-Nambu-Goldstone boson (pNGB) dark matter (DM) model based on an additional non-Abelian gauge symmetry SU(2)D. The gauge symmetry SU(2)D is spontaneously broken to a global custodial symmetry U(1)V via the nonvanishing vacuum expectation values of SU(2)D doublet and triplet scalar fields. Due to the exact global symmetry U(1)V, the lightest U(1)V charged particle becomes stable. We assume that the lightest charged particle in the model is the charged complex pNGB, which we regard as DM. It avoids the strong constraints from current DM direct detection experiments due to the property of NGB. We find that the measured energy density of DM can be reproduced when the DM mass is larger than the half of the Higgs mass, where the lower limit generally comes from the constraint of DM invisible decay and the upper limit from DM direct detection experiments depends on the model parameters.

DOI： 10.1103/PhysRevD.106.115033

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS INC  

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 the F-term as a spurion with the modular weight -2. Their flavor structure is determined by the same symmetry as Yukawa couplings, i.e., fermion masses. The modular symmetric behavior of the mu-term and B-term depends on how the mu-term is generated.

DOI： 10.1093/ptep/ptac152

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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 transformation in order to remove $Z_N$ phases for $Z_N$
twisted boundary condition of matter fields. We compute wave functions of not
only bulk zero modes but also localized modes at the orbifold singular points,
which correspond to new zero modes induced by localized flux. By studying their
Yukawa couplings, it turns out that only three patterns of Yukawa couplings are
allowed. Our theory has a specific coupling selection rule.

arXiv

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Other Link： http://arxiv.org/pdf/2211.04596v1

Language：Others  

Language：Others   Publishing type：Research paper (scientific journal)  

We study a symmetry breaking of residual flavor symmetries realized at fixed
points of the moduli space. In the supersymmetric modular invariant theories, a
small departure of the modulus from fixed points is required to realize fermion
mass hierarchies and sizable CP-breaking effects. We investigate whether one
can dynamically fix the moduli values in the vicinity of the fixed points in
the context of Type IIB string theory. It is found that the string landscape
prefers $|\delta \tau| \simeq 10^{-5}$ for the deviation of the complex
structure modulus from all fixed points and the CP-breaking vacuum is
statistically favored. To illustrate phenomenological implications of
distributions of moduli values around fixed points, we analyze the lepton
sector on a concrete $A_4$ modular flavor model.

DOI： 10.1007/JHEP09(2022)072

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arXiv

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Other Link： http://arxiv.org/pdf/2206.04313v1

Language：Others   Publishing type：Research paper (scientific journal)  

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. In our scenario, wavefunctions in extra
dimensional compact space are modular forms. That leads to constraints on
combinations between modular weights and $\Gamma_N$ ($\Gamma_N')$
representations of matter fields. We also present illustrating examples.

DOI： 10.1103/PhysRevD.106.035001

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arXiv

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Other Link： http://arxiv.org/pdf/2201.04505v1

Language：Others   Publishing type：Research paper (scientific journal)  

We investigate the time evolution of the background spacetime during the
moduli stabilization process, which is assumed to occur in the radiation
dominated era. The setup is basically the Salam-Sezgin model, but we add a
potential term for the dilaton in order to stabilize the moduli completely. We
numerically solve the higher-dimensional background field equations, including
a case that the stabilization process cannot be described within the 4D
effective theory. In contrast to the conventional 4D effective theory analysis,
we find that when the mass scale of the stabilization is larger than the
compactification scale, the radiation contribution to the total energy density
remains to be non-negligible for a much longer time than the stabilization time
scale. As a result, the non-compact 3D space expands slower than the matter
dominated universe. We also find the equation of state for the
radiation~$w_{\rm rad}$ remains to be smaller than 1/3 for a long time, which
indicates that the radiation still feels the extra dimensions for a while even
after the moduli are stabilized.

DOI： 10.1007/JHEP08(2022)120

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arXiv

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Other Link： http://arxiv.org/pdf/2205.00175v1

Language：Others   Publishing type：Research paper (scientific journal)  

We study the lepton flavor violation (LFV), the leptonic magnetic moments
$(g-2)_{\mu,\,e} $ and the electric dipole moment (EDM) of the electron in the
Standard-Model Effective Field Theory with the $\Gamma_N$ modular flavor
symmetry. We employ the stringy Ansatz on coupling structure that 4-point
couplings of matter fields are written by a product of 3-point couplings of
matter fields. We take the level 3 finite modular group, $\Gamma_3$ for the
flavor symmetry, and discuss the dipole operators at nearby fixed point
$\tau=i$, where observed lepton masses and mixing angles are well reproduced.
Suppose the anomaly of the anomalous magnetic moment of the muon to be evidence
of the new physics (NP), we have related it with $(g-2)_{e}$, LFV decays, and
the electron EDM. It is found that the NP contribution to $(g-2)_{e}$ is
proportional to the lepton masses squared likewise the naive scaling. We also
discuss the correlations among the LFV processes $\mu\to e\gamma$, $\tau\to
\mu\gamma$ and $\tau\to e\gamma$, which are testable in the future. The
electron EDM requires the tiny imaginary part of the relevant Wilson
coefficient in the basis of real positive charged lepton masses, which is
related to the $\mu\to e\gamma$ transition in our framework.

DOI： 10.1007/JHEP08(2022)013

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arXiv

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Other Link： http://arxiv.org/pdf/2204.12325v1

Language：Others   Publishing type：Research paper (scientific journal)  

We study the modular symmetric standard-model effective field theory. We
employ the stringy Ansatz on coupling structure that 4-point couplings
$y^{(4)}$ of matter fields are written by a product of 3-point couplings
$y^{(3)}$ of matter fields, i.e., $y^{(4)} = y^{(3)}y^{(3)}$. In this
framework, we discuss the flavor structure of bilinear fermion operators and
4-fermion operators, where the holomorphic and anti-holomorphic modular forms
appear. From the Ansatz, the $A_4$ modular-invariant semileptonic four-fermion
operator $[\,\bar E_R \Gamma E_R][\,\bar D_R \Gamma D_R\,]$ does not lead to
the flavor changing (FC) processes since this operator would be constructed in
terms of gauge couplings $g$ as $y^{(3)} \sim g$. The chirality flipped
bilinear operator $[\,\bar D_R \Gamma D_L\,]$ also does not lead FC if the
mediated mode corresponds to the Higgs boson $H_d$. In this case, the flavor
structure of this operator is the exactly same as the mass matrix. On the other
hand, if the flavor structure of the operator is not the exactly same as the
mass matrix, the situation would change drastically. Then, we obtain the
non-trivial relations of FC transitions at nearby fixed points
$\tau=i,\,\omega\,, i\infty$, which are testable in the future. As an
application, we discuss the relations of the lepton flavor violation processes
$ \mu\to e\gamma,\, \tau\to \mu\gamma$ and $\tau\to e\gamma$ at nearby
$\tau_e=i$, where the successful lepton mass matrix was obtained. We also study
the flavor changing 4-quark operators in the $A_4$ modular symmetry of quarks.
As a result, the minimal flavor violation could be realized by taking relevant
specific parameter sets of order one.

DOI： 10.1103/PhysRevD.105.055022

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arXiv

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Other Link： http://arxiv.org/pdf/2112.00493v2

Language：Others  

Language：Others  

We study the minimal flavor violation in the context of string effective
field theory. Stringy selection rules indicate that $n$-point couplings among
fermionic zero-modes and lightest scalar modes in the string effective action
are given by a product of Yukawa couplings which are regarded as spurion fields
of stringy and geometrical symmetries. Hence, Yukawa couplings determine the
dynamics of flavor and CP violations. This observation strongly supports the
hypothesis of minimal flavor violation in the Standard Model effective field
theory.

DOI： 10.1140/epjc/s10052-022-09986-4

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arXiv

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Other Link： http://arxiv.org/pdf/2108.02700v2

Language：Others   Publishing type：Research paper (scientific journal)  

We examine a common origin of four-dimensional flavor, CP, and $U(1)_R$
symmetries in the context of heterotic string theory with standard embedding.
We find that flavor and $U(1)_R$ symmetries are unified into the $Sp(2h+2,
\mathbb{C})$ modular symmetries of Calabi-Yau threefolds with $h$ being the
number of moduli fields. Together with the $\mathbb{Z}_2^{\rm CP}$ CP symmetry,
they are enhanced to $GSp(2h+2, \mathbb{C})\simeq Sp(2h+2, \mathbb{C})\rtimes
\mathbb{Z}_2^{\rm CP}$ generalized symplectic modular symmetry. We exemplify
the $S_3, S_4, T^\prime, S_9$ non-Abelian flavor symmetries on explicit
toroidal orbifolds with and without resolutions and $\mathbb{Z}_2,S_4$ flavor
symmetries on three-parameter examples of Calabi-Yau threefolds. Thus,
non-trivial flavor symmetries appear in not only the exact orbifold limit but
also a certain class of Calabi-Yau threefolds. These flavor symmetries are
further enlarged to non-Abelian discrete groups by the CP symmetry.

DOI： 10.1007/JHEP01(2022)020

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arXiv

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Other Link： http://arxiv.org/pdf/2107.00487v2

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.nuclphysb.2021.115598

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/JHEP12(2021)017

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/jhep03(2021)161

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.103.126022

Language：Others   Publishing type：Research paper (scientific journal)  

We study the impacts of matter field K"ahler metric on physical Yukawa
couplings in string compactifications. Since the K"ahler metric is non-trivial
in general, the kinetic mixing of matter fields opens a new avenue for
realizing a hierarchical structure of physical Yukawa couplings, even when
holomorphic Yukawa couplings have the trivial structure. The hierarchical
Yukawa couplings are demonstrated by couplings of pure untwisted modes on
toroidal orbifolds and their resolutions in the context of heterotic string
theory with standard embedding. Also, we study the hierarchical couplings among
untwisted and twisted modes on resolved orbifolds.

DOI： 10.1007/JHEP07(2021)064

Language：Others   Publishing type：Research paper (scientific journal)  

We study the modular symmetry of zero-modes on $T_1^2 imes T_2^2$ and
orbifold compactifications with magnetic fluxes, $M_1,M_2$, where modulus
parameters are identified. This identification breaks the modular symmetry of
$T^2_1 imes T^2_2$, $SL(2,mathbb{Z})_1 imes SL(2,mathbb{Z})_2$ to
$SL(2,mathbb{Z})equivGamma$. Each of the wavefunctions on $T^2_1 imes
T^2_2$ and orbifolds behaves as the modular forms of weight 1 for the principal
congruence subgroup $Gamma$($N$), $N$ being 2 times the least common multiple
of $M_1$ and $M_2$. Then, zero-modes transform each other under the modular
symmetry as multiplets of double covering groups of $Gamma_N$ such as the
double cover of $S_4$.

DOI： 10.1007/JHEP11(2020)101

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.physletb.2020.135554

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.102.026004

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.101.106017

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/JHEP05(2020)047

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/JHEP04(2020)001

Language：Others   Publishing type：Research paper (scientific journal)  

We discuss the flavor structure in a resolutions of magnetized
$T^2/mathbb{Z}_2$ orbifold models. The flavor structure of Yukawa couplings
among chiral zero-modes is sensitive to radii of the resolved fixed points of
$T^2/mathbb{Z}_2$ orbifold. We show in concrete models that the realistic mass
hierarchy and mixing angles of the quark sector can be realized at certain
values of blow-up radii, where the number of parameters in the blow-up model
can be smaller than toroidal orbifold one.

DOI： 10.1007/JHEP03(2020)042

Language：Others   Publishing type：Research paper (scientific journal)  

It has been known for some time that a hermitian matrix model with a
Penner-like potential yields as its large-N free energy the prepotential of N=2
N_f=2 SU(2) SUSY gauge theory. We give a rigorous proof that a unitary matrix
model with the identical potential also yields the same prepotential, although
the parameter identifications are slightly different. This result has been
anticipated by Itoyama et. al.

DOI： 10.1016/j.physletb.2019.135075

Language：Others   Publishing type：Research paper (scientific journal)  

We propose matter wavefunctions on resolutions of $T^2/mathbb{Z}_N$
singularities with constant magnetic fluxes. In the blow-down limit, the
obtained wavefunctions of chiral zero-modes result in those on the magnetized
$T^2/mathbb{Z}_N$ orbifold models, but the wavefunctions of
$mathbb{Z}_N$-invariant zero-modes receive the blow-up effects around fixed
points of $T^2/mathbb{Z}_N$ orbifolds. Such blow-up effects change the
selection rules and Yukawa couplings among the chiral zero-modes as well as the
modular symmetry, in contrast to those on the magnetized $T^2/mathbb{Z}_N$
orbifold models.

DOI： 10.1007/JHEP08(2019)046

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.100.025015

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.99.126011

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.99.055035

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DOI： 10.1007/JHEP11(2018)034

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DOI： 10.1007/JHEP05(2018)045

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DOI： 10.1103/physrevd.97.106006

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.physletb.2017.09.062

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.96.046004

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1088/1475-7516/2017/04/042

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.95.063514

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/JHEP01(2017)064

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/PhysRevD.94.126020

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1088/1475-7516/2016/10/013

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/JHEP07(2016)054

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/JHEP05(2016)178

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1093/ptep/ptw038

Language：Others  

New potentials for string axion inflation
© 2016 American Physical Society.We propose a new type of axion inflation with complex structure moduli in the framework of type IIB superstring theory compactified on the Calabi-Yau manifold. The inflaton is identified as the axion for the complex structure moduli whose potential is originating from instantonic corrections appearing through the period vector of the mirror Calabi-Yau manifold. The axionic shift symmetry is broken down to the discrete one by the inclusion of the instantonic correction and certain three-form fluxes. Our proposed inflation scenario is compatible with Kähler moduli stabilization. We also study a typical reheating temperature in the case of complex structure moduli inflation.

DOI： 10.1103/PhysRevD.93.083508

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DOI： 10.1088/1475-7516/2016/01/044

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DOI： 10.1007/JHEP10(2015)008

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DOI： 10.1140/epjc/s10052-012-2018-x

Event date： 2024.8

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Event date： 2024.8

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Event date： 2022.8

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Event date： 2021.11

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Event date： 2021.11

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Event date： 2021.9

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Event date： 2021.8

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Stringy origin of modular flavor symmetry and spontaneous CP violation

Event date： 2021.8

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Event date： 2021.8

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Event date： 2021.3

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Event date： 2020.11

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Event date： 2020.9

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Event date： 2020.2

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Event date： 2020.2

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Event date： 2019.12

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Event date： 2019.9

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Event date： 2019.6

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Event date： 2018.8

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Event date： 2018.7 - 2018.8

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Event date： 2018.7

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Event date： 2018.3

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Event date： 2017.9

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Event date： 2017.6

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Event date： 2016.12

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Event date： 2016.8

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Axion decay constants at special points in type II superstring theory

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Axion decay constants at special points in type II superstring theory

Event date： 2016.7

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Three-generation models from SO(32) heterotic string theory

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New forms of potential for string axion inflation

Event date： 2015.9

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Event date： 2015.6

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Natural inflation with and without modulations in string theory

Event date： 2015.3

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Event date： 2015.1

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Event date： 2014.11

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Event date： 2014.9

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Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc.