Vacuum nonsingular black hole

The spherically symmetric vacuum stress-energy tensor with one assumption concerning its specific form generates the exact analytic solution of the Einstein equations which for larger coincides with the Schwarzschild solution, for smallr behaves like the de Sitter solution and describes a spherically symmetric black hole singularity free everywhere.This essay received the fifth award from the Gravity Research Foundation, 1991     

Decay of cosmological constant in self-consistent inflation

The symmetric vacuum state in gauge theories with spontaneous symmetry breaking is symmetric in both internal and space-time variables. We consider this vacuum state as a Bose condensate of physical Higgs particles, defined over an asymmetric vacuum state, and identify the energy density of their self-interaction with the cosmological constant in the Einstein equation. In this picture, spontaneous symmetry breaking proceeds as decay. Decoherence of coherent oscillations of a scalar field in the course of decay provides the effective mechanism for damping of coherent oscillations, leading to the regime of slow evaporation of a Bose condensate. This mechanism is responsible for self-consistent inflation without fine-tuning of the potential parameters. The physical self-consistency in this model is provided by incorporating the origin of the cosmological constant in the dynamics of spontaneous breaking of particle symmetries. Received: 28 September 2000 / Revised version: 16 January 2001 / Published online: 25 April 2001     

Regular black hole remnants in de Sitter space

We address the question of thermodynamical evolution of regular spherically symmetric cosmological black holes with de Sitter center. Space–time is asymptotically de Sitter as r→0$r\to 0$ and as r→∞$r\to \infty$. A source term in the Einstein equations connects smoothly two de Sitter vacua with different values of cosmological constant and corresponds to anisotropic vacuum dark fluid defined by symmetry of its stress–energy tensor. In the range of masses M_cr1?M?M_cr2$M_{cr1}?M?M_{cr2}$ it describes a regular cosmological black hole with three horizons, an internal horizon ra$r_a$, a black hole horizon rb>ra$r_b>r_a$, and a cosmological horizon rc>rb$r_c>r_b$. Thermodynamical preference for a final product of evaporation is a double-horizon (ra=rb$r_a=r_b$) black hole remnant with the positive specific heat.     

Spherically Symmetric Space-Time with Two Cosmological Constants

We present the analytic spherically symmetric solution of the Einstein equations, which has de Sitter asymptotics for both r and r 0. This two-lambda spherically symmetric solution is globally regular. At the range of mass parameter M_cr1 < M < M_cr2 it has three horizons and describes a neutral black hole whose singularity is replaced by a cosmological constant of Planck or GUT scale, at the background of small . Global structure of space-time contains an infinite sequence of black and white holes, de Sitter-like past and future regular cores (with + at r 0) replacing singularities, asymptotically de Sitter external universes (with for r ), and spacelike infinities. In the range of mass parameter M < M_cr1 we have a one-horizon solution describing recovered selfgravitating particle-like structure at the background of small , and for M > M_cr2 another one-horizon configuration which can be called de Sitter bag. The solutions with M = M_cr1 and M = M_cr2 represent two extreme states of a neutral nonsingular cosmological black hole.     

Chlorophyll and Its Derivatives,Chlorins and Porphyrins,as a Promising Class of Environmentally Friendly Dyes

The possibilities of using pheophorbid (a), chlorin e ₆, its copper complex, 6-N-(2-aminoethylamido)chlorin e ₆ dimethyl ester, and its complexes with Cu(II), Ni(II), Co(II), and Zn(II) as dyes for cellulose, acetate, and wool fibers were studied.     

Silver Nanoparticles: Dependence of the Antimicrobial Activity on the Synthesis Conditions

Russian Journal of General Chemistry - Specific features of the synthesis of stable silver nanoparticles by chemical reduction with agents differing in the reducing ability were studied using...     

Oxidative Degradation of Lignin-Containing Flax Impurities

Russian Journal of General Chemistry - Complex studies of Klason lignin (acid-insoluble residue) were carried out to examine the formation of its water-soluble products. An IR-spectroscopic...     

Effect of surfactant mixtures on electrochemical processes: An estimation by the principle of linearity of free energies

The free-energy linearity principle can be used for interpreting the effect a mixture of surfactants of a common reaction series has on the metal corrosion, passivation, and electrodeposition currents. This follows from the current measurements in the presence of 2–6 component mixtures ofo-oxyazomethin derivatives with allowance for a mole fraction of each component. Dedicated to the ninetieth anniversary of Ya.M. Kolotyrkin’s birth.     

Synthesis of Copper-Silver Bicomponent Nanoparticles in the Presence of Nitrilotrimethylenephosphonic Acid

Synthesis of stable mixed nanoparticles (SMNs) by chemical co-reduction of copper and silver complexonates with sodium borohydride in an open system with the access of air oxygen was studied for the first time the. Variation of the Cu²⁺ to Ag⁺ molar ratio within 1: (0.05–0.5) enabled targeted formation of differently structured nanoparticles (core-shell type), Cu_coreAg_shell and Ag_coreCu_shell. It was found that, by choosing appropriate synthesis conditions, it is possible to produce oxidation-resistant copper particles protected by a shell of a precious metal or to involve the copper complex of nitrilotrimethylenephosphonic acid in silver reduction. The resulting SMNs may become widely used for obtaining various functional materials.