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Takeo Inami

Publications and source records attributed to Takeo Inami.

At least 37 records · Page 2Linked to original sources

Gauge-Higgs Unification In Spontaneously Created Fuzzy Extra Dimensions

We propose gauge-Higgs unification in fuzzy extra dimensions as a possible solution to the Higgs naturalness problem. In our approach, the fuzzy extra dimensions are created spontaneously as a vacuum solution of certain four-dimensional gauge theory. As an example, we construct a model which has a fuzzy torus as its vacuum. The Higgs field in our model is associated with the Wilson loop wrapped on the fuzzy torus. We show that the quadratic divergence in the mass of the Higgs field in the one-loop effective potential is absent. We then argue based on symmetries that the quantum corrections to the Higgs mass is suppressed including all loop contributions. We also consider a realization on the worldvolume theory of D3-branes probing $C^3/(Z_N \times Z_N)$ orbifold with discrete torsion.

hep-ph

Inflaton versus Curvaton in Higher Dimensional Gauge Theories

We construct a model of cosmological inflation and perturbation based on the higher-dimensional gauge theory. The inflaton and curvaton are the scalar fields arising from the extra space components of the gauge field living in more than four dimensions. We take the six-dimensional (6D) Yang-Mills theory compactified on $T^2$ as a toy model, and apply the one-loop effective potential of the inflaton and the curvaton to the curvaton scenario. We have found that the curvaton is subdominant for the linear curvature perturbation, but that a significant non-Gaussianity and a sizable tensor to scalar ratio are generated.

hep-ph

Higgs-Inflaton Potential in Higher-Dimensional SUSY Gauge Theories

We study the possibility that the Higgs and the inflaton are the same single field or cousins arising from the extra space components of some higher-dimensional gauge field. We take 5D supersymmetric gauge theory with a matter compactified on S^1 as a toy model and evaluate the one-loop contribution to the Higgs-inflaton potential. Our gauge-Higgs-inflaton unification picture applied to the gauge field of intermediate energy scale (\sim 10^{13} GeV) can explain the observed inflation parameters without fine-tuning.

hep-th

1/N Expansion of the 2D CP^{N-1} Model on Non(anti)commutative Superspace

We study UV properties of the two-dimensional supersymmetric CP^{N-1} model on non(anti)commutative superspace. We show that the deformed model has the same UV property as the ordinary model in the leading order of 1/N and the deformation give rise to UV divergence which cannot be dealt with in the next-to-leading order.

hep-th

Baryons in AdS/QCD

We construct a holographic model for baryons in the context of AdS/QCD and study the spin-1/2 nucleon spectra and its couplings to mesons, taking fully account of the effects from the chiral symmetry breaking. A pair of 5D spinors is introduced to represent both left and right chiralities. Our model contains two adjustable parameters, the infrared cutoff and the Yukawa coupling of bulk spinors to bulk scalars, corresponding to the order parameter of chiral symmetry. Taking the lowest-lying nucleon mass as an input, we calculate the mass spectrum of excited nucleons and the nucleon couplings to pions. The excited nucleons show a parity-doubling pattern with smaller pion-nucleon couplings.

hep-ph

Non-integrability of Self-dual Yang-Mills-Higgs System

We examine integrability of self-dual Yang-Mills system in the Higgs phase, with taking simpler cases of vortices and domain walls. We show that the vortex equations and the domain-wall equations do not have Painleve property. This fact suggests that these equations are not integrable.

hep-th

Quantum Corrections in 2D SUSY CP^{N-1} Sigma Model on Noncommutative Superspace

We investigate quantum corrections in two-dimensional CP^{N-1} supersymmetric nonlinear sigma model on noncommutative superspace. We show that this model is renormalizable, the N=2 SUSY sector is not affected by the C-deformation and that the non(anti)commutativity parameter C receives infinite renormalization at one-loop order. And it is the renormalizability of the model at one-loop order.

hep-th

Konishi Anomaly and Central Extension in N=1/2 Supersymmetry

We show that the 4-dimensional N=1/2 supersymmetry algebra admits central extension. The central charges are supported by domain wall and the central charges are computed. We also determine the Konishi anomaly for N=1/2 supersymmetric gauge theory. Due to the new couplings in the Lagrangian, many terms appears. We show that these terms sum up to give the expected form for the holomorphic part of the Konishi anomaly. For the anti-holomorphic part, we give a simple argument that the naive generalization has to be modified. We suggest that the anti-holomorphic Konishi anomaly is given by a gauge invariant completion using open Wilson line.

hep-th

Locality, Causality and Noncommutative Geometry

We analyse the causality condition in noncommutative field theory and show that the nonlocality of noncommutative interaction leads to a modification of the light cone to the light wedge. This effect is generic for noncommutative geometry. We also check that the usual form of energy condition is violated and propose that a new form is needed in noncommutative spacetime. On reduction from light cone to light wedge, it looks like the noncommutative dimensions are effectively washed out and suggests a reformulation of noncommutative field theory in terms of lower dimensional degree of freedom. This reduction of dimensions due to noncommutative geometry could play a key role in explaining the holographic property of quantum gravity.

hep-th

Distribution of the distance between opposite nodes of random polygons with a fixed knot

We examine numerically the distribution function $f_K(r)$ of distance $r$ between opposite polygonal nodes for random polygons of $N$ nodes with a fixed knot type $K$. Here we consider three knots such as $\emptyset$, $3_1$ and $3_1 \sharp 3_1$. In a wide range of $r$, the shape of $f_K(r)$ is well fitted by the scaling form of self-avoiding walks. The fit yields the Gaussian exponents $ν_K = {1 \over 2}$ and $γ_K = 1$. Furthermore, if we re-scale the intersegment distance $r$ by the average size $R_K$ of random polygons of knot $K$, the distribution function of the variable $r/R_K$ should become the same Gaussian distribution for any large value of $N$ and any knot $K$. We also introduce a fitting formula to the distribution $g_K(R)$ of gyration radius $R$ for random polygons under some topological constraint $K$.

cond-mat.soft

Supersymmetric CP^N Sigma Model on Noncommutative Superspace

We construct a closed form of the action of the supersymmetric $CP^N$ sigma model on noncommutative superspace in four dimensions. We show that this model has $\mathcal{N}={1/2}$ supersymmetry and that the transformation law is not modified. The supersymmetric $CP^N$ sigma model on noncommutative superspace in two dimensions is obtained by dimensional reducing the model in four dimensions.

hep-th

Average size of random polygons with fixed knot topology

We have evaluated by numerical simulation the average size $R_K$ of random polygons of fixed knot topology $K = \emptyset, 3_1, 3_1\sharp4_1$, and we have confirmed the scaling law $R^2_K \sim N^{2ν_K}$ for the number $N$ of polygonal nodes in a wide range; $N = 100$ -- 2200. The best fit gives $2 ν_K \simeq 1.11$ -- 1.16 with good fitting curves in the whole range of $N$. The estimate of $2 ν_K$ is consistent with the exponent of self-avoiding polygons. In a limited range of $N$ ($N \gtrsim 600$), however, we have another fit with $2 ν_K \simeq 1.01$ -- 1.07, which is close to the exponent of random polygons.

cond-mat.stat-mech

Topics in Nonlinear Sigma Models in D=3

Nonlinear sigma models (NLSM) in d=3 have many interesting and non-trivial features, which were explored poorly in contrast with NLSM in d=2 and d=4. We present a few results from our study of the perturbative and non-perturbative properties of three-dimensional (3D) NLSM. i) We have shown that cancellation of ultra-violet (UV) divergences takes place in 3D extended (N=2,4) supersymmetric NLSM in low orders of the 1/n expansion. ii) We consider noncommutative extension of the 3D CP(n) model, and study low-energy dynamics of BPS solitons in this model. We also discuss briefly dynamics of non-BPS solutions.

hep-th

Non-BPS Solutions of the Noncommutative CP^1 Model in 2+1 Dimensions

We find non-BPS solutions of the noncommutative CP^1 model in 2+1 dimensions. These solutions correspond to soliton anti-soliton configurations. We show that the one-soliton one-anti-soliton solution is unstable when the distance between the soliton and the anti-soliton is small. We also construct time-dependent solutions and other types of solutions.

hep-th

Low-Energy Dynamics of Noncommutative CP^1 Solitons in 2+1 Dimensions

We investigate the low-energy dynamics of the BPS solitons of the noncommutative CP^1 model in 2+1 dimensions using the moduli space metric of the BPS solitons. We show that the dynamics of a single soliton coincides with that in the commutative model. We find that the singularity in the two-soliton moduli space, which exists in the commutative CP^1 model, disappears in the noncommutative model.We also show that the two-soliton metric has the smooth commutative limit.

hep-th

Supersymmetic Extension of the Non-Abelian Scalar-Tensor Duality

The field theory dual to the Freedman-Townsend model of a non-Abelian anti-symmetric tensor field is a nonlinear sigma model on the group manifold G. This can be extended to the duality between the Freedman-Townsend model coupled to Yang-Mills fields and a nonlinear sigma model on a coset space G/H. We present the supersymmetric extension of this duality, and find that the target space of this nonlinear sigma model is a complex coset space, GC/HC.

hep-th