Modern Physics Letters A

There is strong evidence from cosmological data that the universe underwent an epoch of superluminal expansion called inflation. A satisfactory embedding of inflation in fundamental physics has been an outstanding problem at the interface of cosmology and high energy physics. We show how inflation can be realized within the Minimal Supersymmetric Standard Model (MSSM). The inflaton candidates are two specific combinations of supersymmetric partners of quarks and leptons. MSSM inflation occurs at a low scale and generates perturbations in the range experimentally allowed by the latest data from Wilkinson Microwave Anisotropy Probe (WMAP). The parameter space for inflation is compatible with supersymmetric dark matter, and the Large Hadron Collider (LHC) is capable of discovering the inflaton candidates in the allowed regions of parameter space.

A model of a thick brane in 5D bulk supported by two phantom scalar fields is considered. The comparison with a thick brane supported by two usual scalar fields is carried out. The distinctions between a thick brane supported by one usual scalar field and our model have been pointed out.

In this paper we study a new type of lattice gauge model that was proposed in the previous papers for describing unconventional superconductivity (SC). In this model, the Cooper-pair (CP) field is defined on lattice links in order to describe d-wave SC. The CP field can be regarded as a U(1) lattice gauge field dual to the electromagnetic field, and the SC (Higgs) phase transition takes place as a result of the phase coherence of the CP field. Effects of the long-range Coulomb interactions between the CPs and fluctuations of the electromagnetic field are taken into account. We investigate the phase structure of the model and the critical behavior by means of the Monte Carlo simulations. We find that the parameter, which controls the fluxes (vortices) of the CP, strongly influences the phase structure. In three-dimensional case, the model has rich phase structure. In particular, there is a "monopole proliferation" phase transition besides the SC phase transition. Depending on the parameters, this transition exists within the SC phase or takes place simultaneously with the SC transition. This new type of transition is relevant for unconventional SCs with strong spatial three-dimensionality and to be observed by experiments.

After a prologue which clarifies some issues left open in my last paper, the main features of the tetron model of elementary particles are discussed in the light of recent developments, in particular the formation of strong and electroweak vector bosons and a microscopic understanding of how the observed tetrahedral symmetry of the fermion spectrum may arise.

At very high energies we expect that the hadronic cross sections satisfy the Froissart bound, which is a well-established property of the strong interactions. In this energy regime we also expect the formation of the Color Glass Condensate, characterized by gluon saturation and a typical momentum scale: the saturation scale Q_s. In this paper we show that if a saturation window exists between the nonperturbative and perturbative regimes of Quantum Chromodynamics (QCD), the total cross sections satisfy the Froissart bound. Furthermore, we show that our approach allows us to describe the high energy experimental data on total cross sections.

An exact solution of brane universe is studied and the result indicates that Friedmann equations on the brane are modified with an extra term. This term can play the role of dark energy and make the universe accelerate. In order to derive the ΛCDM Universe from this global brane model, the new solutions are obtained to describe the 5D manifold.

The behavior of a Dirac field in a Schwarzschild black hole spacetime is studied. In this work the Hawking temperature and the absorption cross-section for Schwarzschild black hole placed in Dirac field are calculated, taking into consideration the matter waves reflected from the event horizon. The absorption cross-section σ_abs in Dirac field is found to be ⅛ of absorption cross-section in scalar field. The emission spectra of Schwarzschild black hole placed in an environment of Dirac field is also obtained.