Shota Kikuchi 교수

We study the modular symmetry in ${T}^{2}$ and orbifold comfactifications with magnetic fluxes. There are $|M|$ zero modes on ${T}^{2}$ with the magnetic flux $M$. Their wave functions as well as massive modes behave as modular forms of weight $1/2$ and represent the double covering group of $\mathrm{\ensuremath{\Gamma}}\ensuremath{\equiv}SL(2,\mathbb{Z})$, $\stackrel{\texttildelow{}}{\mathrm{\ensuremath{\Gamma}}}\ensuremath{\equiv}\stackrel{\texttildelow{}}{SL}(2,\mathbb{Z})$. Each wave functio

We study the modular symmetry on magnetized toroidal orbifolds with Scherk-Schwarz phases. In particular, we investigate finite modular flavor groups for three-generation modes on magnetized orbifolds. The three-generation modes can be the three-dimensional irreducible representations of covering groups and central extended groups of ${\mathrm{\ensuremath{\Gamma}}}_{N}$ for $N=3$, 4, 5, 7, 8, 16, that is, covering groups of $\mathrm{\ensuremath{\Delta}}(6(N/2{)}^{2})$ for $N=\mathrm{even}$ and c

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 points become hierarchical depending on their residual charges. Thus modular symmetric flavor models in the vicinity of the modular fixed points have a possibility to describe mass hierarchies without fine-tuning. Since describing quark hierarchies without fine-tuning requires ${Z}_{n}$ residual symmetry with $n\ensuremath

A bstract We study A 4 × A 4 × A 4 modular symmetric flavor models to realize quark mass hierarchies and mixing angles without fine-tuning. Mass matrices are written in terms of modular forms. At modular fixed points τ = i∞ and ω , A 4 is broken to Z 3 residual symmetry. When the modulus τ is deviated from the fixed points, modular forms show hierarchies depending on their residual charges. Thus, we obtain hierarchical structures in mass matrices. Since we begin with A 4 × A 4 × A 4 , the residu

Abstract 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 $$\tau =\omega $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>τ</mml:mi> <mml:mo>=</mml:mo> <mml:mi>ω</mml:mi> </mml:mrow> </mml:math> in modular flavor symmetric models. We present models that the NNI forms of the quark mass matrices are simply realized at the fixed point $$\tau =\omega $$ <m

We study a scenario to derive four-dimensional modular flavor symmetric models from a higher-dimensional theory by assuming the compactification consistent with the modular symmetry. In our scenario, wave functions in extra-dimensional compact space are modular forms. That leads to constraints on combinations between modular weights and ${\mathrm{\ensuremath{\Gamma}}}_{N}$ (${\mathrm{\ensuremath{\Gamma}}}_{N}^{\ensuremath{'}}$) representations of matter fields. We also present illustrating examp

Abstract 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 μ-term and B-term depends on how the μ-term is generated.

A bstract 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 fermion zero-mode wave functions in the extra dimensions. Freedoms of constant gauge fields, called Scherk-Schwarz phases are taken into account. We classify three-generation models in a systematic manner, clarifying the relationship between different models. The Higgs sector is also studied by analyzing possible assi

We study the modular symmetry in magnetized <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>T</a:mi><a:mrow><a:mn>2</a:mn><a:mi>g</a:mi></a:mrow></a:msup></a:math> torus and orbifold models. The <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi>T</c:mi><c:mrow><c:mn>2</c:mn><c:mi>g</c:mi></c:mrow></c:msup></c:math> torus has the modular symmetry <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msub><e:m

A bstract 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

We study the modular symmetry anomaly in magnetized orbifold models. The nonperturbative effects such as D-brane instanton effects can break tree-level symmetry. We study which part of the modular symmetry is broken explicitly by Majorana mass terms with three generations of neutrinos. The modular weight of neutrino mass terms does not match with other coupling terms in the tree-level Lagrangian. In addition, the ${Z}_{N}$ symmetry of the modular flavor symmetry is broken and a certain normal su

Abstract We study the CP violation and the CP phase of quark mass matrices in modular flavor symmetric models. The CP symmetry remains at τ = e2πi/3 by a combination of the T-symmetry of the modular symmetry. However, T-symmetry breaking may lead to CP violation at the fixed point τ = e2πi/3. We study such a possibility in magnetized orbifold models as examples of modular flavor symmetric models. These models, in general, have more than one candidate for Higgs modes, while generic string compact

We study quark and lepton flavor structures on magnetized $T^2/\mathbb{Z}_2$ twisted orbifold model. There are 6,460 number of flavor models but most of them cannot lead to realistic flavor observables because of the difficulties on realizing mass hierarchies and small (large) mixing angles of quarks (leptons). We find that certain zero point patterns of zero-modes of fermions and Higgs fields give the flavor models being able to avoid these difficulties. We classify such flavor models and show

In recent years, smart-agri has gained attention in the agricultural sector as a mean to improve efficiency and address labor shortages. However, despite being a key industry in high-temperature, humid regions such as Okinawa Prefecture and the Nansei Islands of Kagoshima Prefecture, and the need for stable yields, sugarcane cultivation has seen little progress in smart-agri implementation. This paper proposes an autonomous navigation system using a crawler robot for collecting image data of sug