<Emphasis Type="Italic">SU</Emphasis>(2) x <Emphasis Type="Italic">SU</Emphasis>(2) nonlocal quark model with confinement

The nonlocal version of the SU(2) x SU(2) symmetric four-quark interaction of the NJL type is considered. Each of the quark lines contains the form factors. These form factors remove the ultraviolet divergences in quark loops. The additional condition on the quark mass function m(p) ensures the absence of the poles in the quark propagator (quark confinement). The constituent-quark mass m(0) is expressed through the cut-off parameter , MeV in the chiral limit. These parameters are fixed by the experimental value of the weak pion decay and allow us to describe the mass of the light scalar meson, the strong decay and the D/S ratio in the decay in satisfactory agreement with the experimental data.Received: 16 June 2003, Revised: 28 July 2003, Published online: 18 December 2003PACS: 14.40.-n Mesons - 11.10.Lm Nonlinear or nonlocal theories and models - 12.39.Ki Relativistic quark model     

A reanalysis of finite temperature <Emphasis Type="Italic">SU</Emphasis>(<Emphasis Type="Italic">N</Emphasis>) gauge theory

We revise the SU(N _c ), N _c =3,4,6, lattice data on pure gauge theories at finite temperature by means of a quasi-particle approach. In particular, we focus on the relation between the effective mass of the quasi-particle and the order of the deconfinement transition, the scaling of the interaction measure with N²_c -1N^{2}_{c} -1, the role of gluon condensate, and the screening mass.     

A Pseudo-cocycle for the Comultiplication on the Quantum <Emphasis Type="Italic">SU</Emphasis>(<Emphasis Type="Italic">2</Emphasis>) Group

We show that the comultiplication on the quantum group SU _q (2) may be obtained from that on the quantum semigroup SU ₀(2) by twisting with a unitary 2-pseudo-cocycle. Work supported by the ARC Linkage International Fellowship LX0667294, and by the Korea Research Foundation Grant (KRF-2004-041-C00024).     

Contracted Hamiltonian on Symmetric Space <Emphasis Type="Italic">SU</Emphasis>(3)/<Emphasis Type="Italic">SU</Emphasis>(2) and Conserved Quantities

We study the quantum model on symmetric space SU(3)/SU(2). By using the Inonu-Wigner contraction to Lie algebra su(3), we arrive at a special case of three-body Sutherland model. It has shown that by calculating conservative quantities of this model, it has Poincare Lie algebra, too.     

Entropy for <Emphasis Type="Italic">SU</Emphasis>(3)<Subscript><Emphasis Type="Italic">c</Emphasis></Subscript> quark states

We discuss the quantum state structure using the standard model for three colored quarks in the fundamental representations of SU(3)_c making up the singlet ground state of the hadrons. This allows us to calculate a finite von Neumann entropy from the quantum reduced density matrix, which we explicitly evaluate for the quarks in a model for the meson and baryon states.Received: 9 December 2003, Revised: 23 January 2004, Published online: 8 April 2004D.E. Miller: om0@psu.eduPermanent address: Department of Physics, Pennsylvania State University, Hazleton Campus, Hazleton, Pennsylvania, 18201 USA     

<Emphasis Type="Italic">O</Emphasis>(1) eV sterile neutrino in <Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">R</Emphasis>) gravity

We refer [1] to the role of an additional O(1) eV sterile neutrino in modified gravity models. We find parameter constraints in particular f(R) gravity model using following up-to-dated cosmological data: measurements of the cosmic microwave background (CMB) anisotropy, the CMB lensing potential, the baryon acoustic oscillations (BAO), the cluster mass function and the Hubble constant. It was obtained for the sterile neutrino mass 0.47 eV < m _ν,sterile < 1 eV (2σ) assuming that the sterile neutrinos are thermalized and the active neutrinos are massless, not significantly larger than in the standard cosmology model within the same data set: 0.45 eV < m _ν,sterile < 0.92 eV (2σ). But, if the mass of sterile neutrino is fixed and equals ≈ 1.5 eV according to various anomalies in neutrino oscillation experiments, f(R) gravity is much more consistent with observation data than the CDM model.     

<Emphasis Type="Italic">SU</Emphasis>(3)-Instantons and <Emphasis Type="Italic">G</Emphasis><Subscript>2</Subscript>,<Emphasis Type="Italic">Spin</Emphasis>(7)-Heterotic String Solitons

Necessary and sufficient conditions to the existence of a hermitian connection with totally skew-symmetric torsion and holonomy contained in SU(3) are given. A formula for the Riemannian scalar curvature is obtained. Non-compact solution to the supergravity-type I equations of motion with non-zero flux and non-constant dilaton is found in dimension 6. Non-conformally flat non-compact solutions to the supergravity-type I equations of motion with non-zero flux and non-constant dilaton are found in dimensions 7 and 8. A Riemannian metric with holonomy contained in G₂ arises from our considerations and Hitchin’s flow equations, which seems to be new. Compact examples of SU(3),G₂ and Spin(7) instanton satisfying the anomaly cancellation conditions are presented.     

Trace anomaly and quasi-particles in finite temperature <Emphasis Type="Italic">SU</Emphasis>(<Emphasis Type="Italic">N</Emphasis>) gauge theory

We consider deconfined matter in SU(N) gauge theory as an ideal gas of transversely polarized quasi-particle modes having a temperature-dependent mass m(T). Just above the transition temperature, the mass is assumed to be determined by the critical behavior of the energy density and the screening length in the medium. At high temperature, it becomes proportional to T as the only remaining scale. The resulting (trace anomaly based) interaction measure Δ=(ϵ−3P)/T ⁴ and energy density are found to agree well with finite temperature SU(3) lattice calculations.     

On the degeneracy of <Emphasis Type="Italic">SU</Emphasis>(3)<Subscript><Emphasis Type="Italic">k</Emphasis></Subscript> topological phases

The ground state degeneracy of an SU(N) _k topological phase with n quasiparticle excitations is a relevant quantity for quantum computation, condensed matter physics, and knot theory. It is an open question to find a closed formula for this degeneracy for any N >2. Here we present the problem in an explicit combinatorial way and analyze the case N = 3. While not finding a complete closed-form solution, we obtain generating functions and solve some special cases.     

<Emphasis Type="Italic">SU</Emphasis>(2|1) supersymmetric mechanics as a deformation of <Emphasis Type="Italic">N</Emphasis> = 4 mechanics

We give a brief review of SU(2|1) supersymmetric quantum mechanics based on the worldline realizations of the supergroup SU(2|1) in the appropriate N = 4, d = 1 superspaces. The corresponding SU(2|1) models are deformations of standard N = 4, d = 1 models by a mass parameter m.     

<Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">R</Emphasis>) Cosmology from <Emphasis Type="Italic">q</Emphasis>-theory

From a macroscopic theory of the quantum vacuum in terms of conserved relativistic charges (generically denoted by q ^(a) with label a), we have obtained, in the low-energy limit, a particular type of f(R) model relevant to cosmology. The macroscopic quantum-vacuum theory allows us to distinguish between different phenomenological f(R) models on physical grounds. The text was submitted by the authors in English.     

<Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">R</Emphasis>) global monopole revisited

In this paper the f(R) global monopole is reexamined. We provide an exact solution for the modified field equations in the presence of a global monopole for regions outside its core, generalizing previous results. Additionally, we discuss some particular cases obtained from this solution. We consider a setup consisting of a possible Schwarzschild black hole that absorbs the topological defect, giving rise to a static black hole endowed with a monopole’s charge. Besides, we demonstrate how the asymptotic behavior of the Higgs field far from the monopole’s core is shaped by a class of spacetime metrics which includes the ones analyzed here. In order to assess the gravitational properties of this system, we analyze the geodesic motion of both massive and massless test particles moving in the vicinity of such configuration. For the material particles we set the requirements they have to obey in order to experience stable orbits. On the other hand, for the photons we investigate how their trajectories are affected by the gravitational field of this black hole.     

Temperature dependence of dark current-voltage characteristics of <Emphasis Type="Italic">n</Emphasis>InSb-<Emphasis Type="Italic">n</Emphasis>PbTe-<Emphasis Type="Italic">n</Emphasis>CdTe isotype structure

The temperature dependence of dark current-voltage characteristics of an nInSb-nPbTe-nCdTe structure is investigated. It is shown that in the temperature range from 115 K to 125 K an energy barrier exists for charge carriers through the InSb layer, which is strictly connected with different temperature dependences of electron concentrations in nInSb and nPbTe.     

Notes on integrable boundary interactions of open <Emphasis Type="Italic">SU</Emphasis>(4) alternating spin chains

Ref. [J. High Energy Phys. 1708, 001 (2017)] showed that the planar flavored Ahanory-Bergman-Jafferis-Maldacena (ABJM) theory is integrable in the scalar sector at two-loop order using coordinate Bethe ansatz. A salient feature of this case is that the boundary reflection matrices are anti-diagonal with respect to the chosen basis. In this paper, we relax the coefficients of the boundary terms to be general constants to search for integrable systems among this class. We found that the only integrable boundary interaction at each end of the spin chain aside from the one in ref. [J. High Energy Phys. 1708, 001 (2017)] is the one with vanishing boundary interactions leading to diagonal reflection matrices. We also construct non-supersymmetric planar flavored ABJM theory which leads to trivial boundary interactions at both ends of the open chain from the two-loop anomalous dimension matrix in the scalar sector.     

<Emphasis Type="Italic">SU</Emphasis>(2) Non-Abelian Photon

In this paper, we have proposed S U(2) non-Abelian electromagnetism gauge theory. In the theory, photon has self-interaction and interaction between them, which can explain photon entanglement phenomenon in quantum information. Otherwise, we find there are three kinds photons γ ⁺, γ ^? and γ ⁰, they have electric charge + e _γ , ? e _γ and 0, respectively, these prediction are accordance with some experiment results.     

New types of <Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">T</Emphasis>) gravity

Recently f(T) theories based on modifications of teleparallel gravity, where torsion is the geometric object describing gravity instead of curvature, have been proposed to explain the present cosmic accelerating expansion. The field equations are always second order, remarkably simpler than f(R) theories. In analogy to the f(R) theory, we consider here three types of f(T) gravity, and find that all of them can give rise to cosmic acceleration with interesting features, respectively.     

Accelerating universe from <Emphasis Type="Italic">F</Emphasis>(<Emphasis Type="Italic">T</Emphasis>) gravity

It is shown that the acceleration of the universe can be understood by considering a F(T) gravity models. For these F(T) gravity models, a variant of the accelerating cosmology reconstruction program is developed. Some explicit examples of F(T) are reconstructed from the background FRW expansion history.     

Noether symmetries in <Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">G</Emphasis>) gravity

We explore Noether symmetries of the Friedmann–Robertson–Walker universe model in modified Gauss–Bonnet gravity for both vacuum and nonvacuum (dust fluid) cases. We evaluate symmetry generators and the corresponding conserved quantities by using separation of variables and a power-law form. We construct exact f(G) models and study accelerating expansion of the universe in terms of a scale factor, deceleration, and the EoS parameters. We also check the validity of energy conditions through the weak energy conditions for our constructed model. The state finder parameters indicate the resemblance of our constructed models to the ΛCDM model. We conclude that our results are consistent with the recent astrophysical observations.     

Horizon thermodynamics in <Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">R</Emphasis>) theory

We investigate whether the new horizon first law proposed recently still work in f(R) theory. We identify the entropy and the energy of black hole as quantities proportional to the corresponding value of integration, supported by the fact that the new horizon first law holds true as a consequence of equations of motion in f(R) theories. The formulas for the entropy and energy of black hole found here are in agreement with the results obtained in literatures. For applications, some nontrivial black hole solutions in f(R) theories have been considered, the entropies and the energies of black holes in these models are firstly computed, which may be useful for future researches.     

Reconstruction of some cosmological models in <Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">R</Emphasis>,<Emphasis Type="Italic">T</Emphasis>) cosmology

In this paper, we reconstruct cosmological models in the framework of f(R,T) gravity, where R is the Ricci scalar and T is the trace of the stress-energy tensor. We show that the dust fluid reproduces ΛCDM, phantom–non-phantom era and phantom cosmology. Further, we reconstruct different cosmological models, including the Chaplygin gas, and scalar field with some specific forms of f(R,T). Our numerical simulation for the Hubble parameter shows good agreement with the BAO observational data for low redshifts, z<2.