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PARTICLE NUMBER PRODUCTION AND TIME VARIATION WITH NON-EQUILIBRIUM QUANTUM FIELD THEORY // Tomsk State Pedagogical University Bulletin. 2012. Issue 13 (128). P. 61-65

We study the particle number production and its time variation using non-equilibrium quantum eld theory. We study the model proposed by Hotta et.al. [1] for particle number production with a heavy neutral scalar and a light complex scalar. The interaction Lagrangian contains CP violating phase and particle number violating interaction among the scalars. The particle number violating mass term is also introduced, which splits a complex scalar into two real scalars with small non-degenerate mass. Therefore, the term generates particle and anti-particle mixing. We study the long time behavior of the particle number production rate.

Keywords: particle number production, non-equilibrium quantum eld theory

BRST APPROACH TO GAUGE INVARIANT HIGHER SPIN THEORY OF CONFORMAL FIELD IN FLAT SPACE // Tomsk State Pedagogical University Bulletin. 2012. Issue 13 (128). P. 155-158

We propose a closed higher-spin algebra and its representation that reproduces conformal invariant Lagrangian presented by Fradkin and Tseytlin. We use this algebra for constructing gauge invariant Lagrangian by BRST method. Lagrangian constructed by BRST method does not have any off-shell constraints or higher derivative terms as in the non-conformal case. As an example for spin 2 case in four space-time dimension, our Lagrangian agrees with that of conformal gravity by using gauge xing and equations of motions of auxiliary fields.

Keywords: higher-spin, BRST, conformal

GAUGE INVARIANT LAGRANGIAN FORMULATIONS FOR MIXED-ANTISYMMETRIC FERMIONIC HIGHER SPIN FIELDS // Tomsk State Pedagogical University Bulletin. 2014. Issue 12 (153). P. 243-248

A Lagrangian formulation of irreducible half-integer higher-spin representations of the Poincare algebra with a Young tableaux having two columns is presented based on the BRST approach. Starting from Casimir constraints written by oscillator representation of Poincare algebra, which is the necessary condition of the irreducibility, we find closed higher spin superalgebra. In order to convert all constraints to the first class we introduce four auxiliary oscillators with γ-matrix and use Verma module method. To get nilpotent BRST operators we further introduce ghosts. After using restrictions on spin number and ghost number we construct Lagrangian having gauge symmetry with finite stage of reducibility.

Keywords: higher-spin fields, gauge theories, BRST method, Lagrangian formulation