arXiv subjects

Yoshio Matsumoto

Publications and source records attributed to Yoshio Matsumoto.

5 recordsLinked to original sources

arXiv2023

The Effects of Android Robots Displaying Emotion on Humans: Interactions between Older Adults and Android Robots

Often robots are seen as a means to an end to fulfill a logical objective task. Android robots, on the other hand, provide new possibilities to fulfill emotional tasks and could therefore be integrated into assistive scenarios. We explored this possibility by letting older adults and stakeholders have a conversation with an android robot capable of expressing emotion through facial expressions. The study was carried out with a wizard-of-oz approach and data collected with a mixed methods approach. We found that the participants were encouraged to speak more with the robot due to its smile. Simultaneously, many ethical questions were raised about transparency and manipulation. Our research can give valuable insight into the reaction of older adults to android robots that show emotions.

cs.HC↗

arXiv2022

Gravitational relaxation of electroweak hierarchy problem

In the present paper, we discuss gravitational relaxation models for the electroweak hierarchy problem. We show that modified gravity can naturally relax the electroweak hierarchy problem where conformal transformation provides a crucial rule about what modified gravity theories are favored to relax the electroweak hierarchy. The conformal transformation connects different gravitational theories and rescaling the metric changes the dimensional parameters like the Higgs mass or the cosmological constant in different frames drastically. When the electroweak scale is naturally realized by dynamical and running behavior of dilatonic scalar field or scaling parameter, the modified gravity theories can relax the electroweak hierarchy problem. We discuss the theoretical and phenomenological validity of the gravitational relaxation models.

hep-ph↗

arXiv2019

Revisiting regularization with Kaluza-Klein states and Casimir vacuum energy from extra dimensional spaces

In the present paper, we investigate regularization of the one-loop quantum corrections with infinite Kaluza-Klein (KK) states and evaluate Casimir vacuum energy from extra dimensions. The extra dimensional models always involve the infinite massless or massive Kaluza-Klein states, and therefore, the regularization of the infinite KK corrections is highly problematic. In order to avoid the ambiguity, we adopt the proper time integrals and the Riemann zeta function regularization in evaluating the summations of infinite KK states. In the calculation, we utilize the KK regularization method with exchanging the infinite summations and the infinite loop integrals. At the same time, we also evaluate the correction by the the dimensional regularization method without exchanging the summations and the loop integrals. Then, we clearly show that the regularized Casimir corrections from the KK states have the form of $\propto 1/R^2$ for the Higgs mass and $\propto 1/R^4$ for the cosmological constant, where $R$ is the compactification radius. We also evaluate the Casimir energy in supersymmetric extra-dimensional models. The contributions from bulk fermions and bulk bosons are not offset because we choose SUSY breaking boundary conditions. The non-zero supersymmetric Casimir corrections from extra dimensions undoubtedly contribute to the Higgs mass and the cosmological constant. We conclude the coefficients of such corrections are enhanced compared to the case without bulk supersymmetry.

hep-ph↗

arXiv2016

Yukawa couplings in 6D gauge-Higgs unification on $T^2/Z_N$ with magnetic fluxes

We discuss the Yukawa couplings in 6D gauge-Higgs unification models on $T^2/Z_N$ in the presence of magnetic fluxes. We provide general formulae for them, and numerically evaluate their magnitude in a specific model on $T^2/Z_3$. Thanks to the nontrivial profiles of the zero-mode wave functions, the top quark Yukawa coupling can be reproduced without introducing a large representation of the gauge group for matter fields. However, it is difficult to realize small Yukawa couplings only by the magnetic fluxes and the Wilson-line phases because of the complicated structure of the mode functions on $T^2/Z_N$ ($N=3,4,6$).

hep-ph↗

arXiv2014

6D gauge-Higgs unification on T^2/Z_N with custodial symmetry

We investigate the gauge-Higgs unification models compactified on T^2/Z_N that have the custodial symmetry. We select possible gauge groups, orbifolds and representations of the matter fermions that are consistent with the custodial symmetry, by means of the group theoretical analysis. The best candidate we found is 6D SU(3)_C x U(4) gauge theory on T^2/Z_3 and the third generation quarks are embedded into bulk fermions that are the symmetric traceless rank-2 tensor of SO(6).

hep-ph↗