International Journal of Modern Physics A

This is a pedagogical and self-contained review on obtaining electroweak precision constraints on TeV scale new physics using the effective theory method. We identify a set of relevant effective operators in the Standard Model and calculate from them corrections to all major electroweak precision observables. The corrections are compared with data to put constraints on the effective operators. Various approaches and applications in the literature are reviewed.

This paper is devoted to detailed investigations of free scalar field theory on κ-Minkowski space. After reviewing necessary mathematical tools, we discuss in detail the Lagrangian and solutions of field equations. We analyze the space–time symmetries of the model and construct the conserved charges associated with translational and Lorentz symmetries. We show that the version of the theory usually studied breaks Lorentz invariance in a subtle way: there is an additional trans-Planckian mode present, and an associated conserved charge (the number of such modes) is not a Lorentz scalar.

A general approach for investigating Bianchi-V cosmological models is introduced in a scalar-tensor theory of gravitation proposed by Saez and Ballester in which the law of variation for Hubble's parameter is taken into account. This variation for Hubble's parameter that yields a constant value of deceleration parameter is then utilized to solve the field equations governing anisotropic Bianchi-V space–time filled with perfect fluid. Two types of exact solutions that correspond to singular and nonsingular models are presented. Finally, we arrive to the conclusion that the universe decelerates for positive value of deceleration parameter whereas it accelerates for negative one. The behaviors of observationally important parameters are discussed in detail. Exact expressions for look-back time, luminosity distance and event horizon versus redshift are derived and their significance are discussed in detail. It has been observed that the solutions are compatible with the results of recent observations.

Bosonic formulation of the negative energy sea, so-called Dirac sea, is proposed by constructing a hole theory for bosons as a new formulation of the second quantization of bosonic fields. The original idea of Dirac sea for fermions, where the vacuum state is considered as a state completely filled by fermions of negative energy and holes in the sea are identified as antiparticles, is extended to boson case in a consistent manner. The bosonic vacuum consists of a sea filled by negative energy bosonic states, while physical probabilities become always positive definite. We introduce a method of the double harmonic oscillator to formulate the hole theory of bosons. Our formulation is also applicable to supersymmetric field theory. The sea for supersymmetric theories has an explicit supersymmetry. We suggest applications of our formulations to the anomaly theories and the string theories.

In bosonic formulation of the negative energy sea, so-called Dirac sea presented in the preceding paper [arXiv:hep-th/0603242], one of the crucial points is how to construct a positive definite inner product in the negative energy states, since naive attempts would lead to nonpositive definite ones. In the preceding paper, the nonlocal method is used to define the positive definite inner product. In the present paper we, make use of a kind of ∊-regularization and renormalization method which may clarify transparently the analytical properties of our formulation.

We investigate the Hawking radiation of black p-branes of superstring theories using the method of anomaly cancellation, specially, we use the method of S. Iso, H. Umetsu and F. Wilczek, Phys. Rev. Lett.96, 151302 (2006) and Phys. Rev. D74, 044017 (2006). The metrics of black p-branes are spherically symmetric, but not the Schwarzschild-type. In order to simplify the calculation, we first make a coordinate transformation to transform the metric to the Schwarzschild-type. Then we calculate its energy–momentum flux from the method of anomaly cancellation of the above-mentioned references. The obtained energy–momentum flux is equal to a blackbody radiation, the thermodynamic temperature of the radiation is equal to its Hawking temperature. And we find that the results are not changed for the original non-Schwarzschild-type spherically symmetric metric.

The structure of a protoplanet has been determined by numerical method in which the protoplanet is assumed to be a gaseous sphere of solar composition having Jovian mass, which is in a steady state of quasistatic equilibrium. It is also assumed that the only source of energy in a protoplanet is gravitational. Regarding the transference of heat inside the protoplanet, we have considered two cases of interest (i) the convective case and (ii) the conductive–radiative case. It is found that in both cases the system possesses unique solution.

This paper analyzes the long-range correlation property and the corresponding multifractal structure of the distribution of shower particles in central Au + Au collisions at 200 A GeV by using the Multifractal Detrended Fluctuation Analysis method. The result shows that the pseudorapidity and azimuthal distributions of shower particles are multifractals in those collisions.