Calculation of the energy-momentum tensor of the vacuum in an anisotropic universe

Subtractive methods (N-wave and adiabatic) which are applicable to the calculation of the energy-momentum tensor of quantum fields in curved space-time are in need of a foundation in terms of renormalizations. In the example of a scalar field in an anisotropic universe of Bianchi type I it is shown that the Pauli-Villars scheme, in which the renormalization is in fact realized separately in each mode, provides such a foundation. The technical difficulty obstructing the explicit regularization of divergent integrals in momentum space is shown. We calculate the polarization of the vacuum of a scalar field with arbitrary coupling to the curvature in a weakly anisotropic universe.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 93–98, July, 1986.     

Nonlinear electrodynamics and particle-like solutions with consideration of gravitation

The question of existence of various forms of spherically symmetric particle-like solutions within the theory of general relativity with nonlinear electromagnetic fields is considered. Such solutions are those with a regular center and those with a throat and second spatial asymptote. It will be shown that in the given class of theories: 1) particle-like solutions with nonzero magnetic charge do not exist, and 2) particle-like solutions do not exist for gauge invariant Lagrangians. For the class of Lagrangians with explicit dependence upon potential, particle-like solutions of both types are obtained and limits of their parameters are determinedTranslated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 36–40, September, 1989.     

Scalar field and gravitational instability

We study monopole perturbations of spherically symmetric scalar-vacuum and scalar-electrovacuum fields in general relativity and reduce the problem to a one-dimensional Schrödinger-like equation with a certain effective potential. Imposing certain boundary conditions, we select physically meaningful perturbations. Some of them grow exponentially and we conclude that the background system is unstable.     

Synthesis,structure, and thermal properties of polyrotaxanes derived from β-cyclodextrin and polydimethylsiloxane

Supramolecular inclusion complexes, polyrotaxanes, of β-cyclodextrin with modified polydimethylsiloxane were prepared. The structure and thermal properties of these complexes were studied as influenced by the preparation conditions, component ratio, and molecular weight of the polymer.     

Inverted black holes and anisotropic collapse

The structure of static vacuum and electrovacuum fields with the most simple symmetry is discussed within the framework of the general theory of relativity. The general electrovacuum fields with plane and pseudospherical symmetries and the special case of fields with cylindrical symmetry contain horizons with the R and T regions interchanged by comparison with the Schwarzschild solution (the inverted black hole structure); the horizons disappear in the presence of a massless scalar field and for small deviations from plane symmetry. The physical consequences of this structure for the simplest models of anisotropic collapse are briefly discussed. A simple method is described for constructing the Penrose diagrams for a given metric, and examples are given of the construction of new diagrams for the electrovacuum solutions with a term.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 32–38, June, 1979.     

Statistical Analysis of Microdomain Ensembles on the Surface of Poly(4,4'-oxyphenylenepyromellitimide) Films in the Course of Imidization

The statistical ensembles of supramolecular formations (microdomains) on the surface of films of the polyamido acid derived from pyromellitic dianhydride and 4,4'-oxydiphenylenediamine and evolution of these ensembles in the course of thermal and chemical imidization were studied using the reversible aggregation model. The regular trends in variation of the distribution parameters (aggregation energy and mean microdomain size) in the course of thermal imidization were established. The distribution parameters were compared for polyimide films prepared by thermal and chemical imidization.     

Structure and thermal properties of polyrotaxanes derived from γ-cyclodextrin and modified polydimethylsiloxane

Supramolecular inclusion complexes, polyrotaxanes, derived from γ-cyclodextrin and polydimethylsiloxane modified with terminal epoxy groups were studied. The dependence of the structure, morphology, and thermal properties of polyrotaxanes on the molecular weight of the linear polymer, molar ratio of γ-cyclodextrin and polymer, and presence of free γ-cyclodextrin in the complexes was examined.