Five-dimensional Kaluza-Klein black holes coupled to massive scalar particles

Spherically symmetric solutions coupled to massive scalar particles in five-dimensional Kaluza-Klein theory are obtained. The solutions contain two event horizons. The inner horizon corresponds to the Schwarzschild black hole and the outer one is a new horizon which is produced by the massive scalar particles. It is found that the massive modes contribute an effective cosmological constant to the four-dimensional Einstein theory.     

Phantom scalar fields in five-dimensional Kaluza-Klein theory

The existence of a so-called "phantom" scalar field in some Riemannian spaceV ₄, i.e., a field in which the effective energy momentum tensorT ^(sf) vanishes in the five-dimensional Kaluza-Klein theory, is investigated by means of the integrability conditions for relations of the form _;;=k_,,+bg found in [6]. Phantom fields are found in homogeneous isotropic cosmological models.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 50–56, February, 1996.     

Black holes and membranes in higher-dimensional theories with dilaton fields

We consider scale invariant theories which couple gravity to Maxwell fields and antisymmetric tensor fields with a dilaton field. We exhibit in a unified way solutions representing black hole, space-time membrane, vortex and cosmological solutions. Their physical properties depend sensitively on the coupling constant of the dilaton field, there being critical value separating qualitatively different types of behaviour, e.g. the temperature of a charged black hole in the extreme limit. It is also shown that compactification into the 4-dimensional Minkowski space in terms of a membrane solution is possible in 10-dimensional supergravity model.     

Black holes with scalar charge

Previously it had been thought that a stationary black hole with an exterior devoid of matter can be parametrized only by mass, angular momentum, and electric charge. We show here that scalar charge is also an admissible parameter. Our starting point is a new solution of Einstein's equations with stress-energy of electromagnetic and conformal scalar fields which we presented earlier. It has a black-hole geometry, and is parametrized by electric and scalar charges. Its conformal scalar field is unbounded at the event horizon, and we originally regarded this feature as incompatible with a black hole interpretation. However, following a suggestion of B. DeWitt, we show here that the infinity in the scalar field need not be physically pathological: it is not associated with an infinite potential barrier for test scalar charges; it does not cause the termination of any trajectories of these test particles at finite proper time; and it is not connected with unbounded tidal accelerations between neighboring trajectories. In view of these facts, we now regard the new solution as a genuine black hole solution.     

Plane-wave solutions in higher-dimensional Kaluza-Klein theories

Exact solutions representing mixed plane-gravitational waves and planewaves of scalar fields and non-Abelian gauge fields in higher-dimensional Kaluza-Klein theories are obtained under the generalized higher-dimensional harmonic condition. Two special cases are discussed.     

Strongly coupled chameleon fields: new horizons in scalar field theory

We show that, as a result of nonlinear self-interactions, scalar field theories that couple to matter much more strongly than gravity are not only viable but could well be detected by a number of future experiments provided that they are properly designed to do so.     

Imitation of matter by a scalar field in five-dimensional Kaluza-Klein theory

The interpretation of the scalar field ={ie96-1} in the five-dimensional variant of Kaluza-Klein theory is considered. It is proposed that the scalar field be considered as the generalized potential of four material velocities. It can be shown that with additional limitations on the scalar field the right side of the split five-dimensional Einstein equations transform to a hydrodynamic energy-momentum tensor for an ideal liquid with a limited set of equations of state. Concrete five-dimensional metrics, which are obligatorily nonstationary, are analyzed from this viewpoint.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 111–117, January, 1995.     

Stringy corrections to Kaluza-Klein black holes

We consider string theory corrections to 4D black holes which solve the 5D vacuum Einstein equations. We find that the corrections vanish only for the extremal electric solution. We also show that for the non-extremal electric black hole the mass corrections are related to the charge corrections. The implications to string states counting and the correspondence principle for black holes and strings are discussed.     

Spinor fields in the nonsymmetric,non-Abelian Kaluza-Klein theory

Spinor fields are considered in the framework of the nonsymmetric Kaluza-Klein theory and the nonsymmetric Jordan-Thiry theory (in non-Abelian case). Dipole moments for fermions of value 10^–31 and pseudomass-like terms are found.     

Black holes and information theory

During the past three decades investigators have unveiled a number of deep connections between physical information and black holes whose consequences for ordinary systems go beyond what has been deduced purely from the axioms of information theory. After a self-contained introduction to black hole thermodynamics, we review from its vantage point topics such as the information conundrum that emerges from the ability of incipient black holes to radiate, the various entropy bounds for non-black hole systems (holographic bound, universal entropy bound, etc.) which are most easily derived from black hole thermodynamics, Bousso's covariant entropy bound, the holographic principle of particle physics, and the subject of channel capacity of quantum communication channels.     

Effective Hamiltonian for non-minimally coupled scalar fields

In the post Newtonian limit, a non-relativistic Hamiltonian is derived for scalar fields with quartic self-interaction and non-minimal coupling to the curvature scalar of the background spacetime. These effects are found to contribute to the non-relativistic Hamiltonian by adding nonlinearities and by modifying the gravitational Darwin term. As we discuss briefly in the text, the impact of these novel structures can be sizable in dense media like neutron star core, and can have observable signatures in phase transitions, for example.     

Perturbation theory and non-renormalizable scalar fields

We study how to set up systematic summation rules that could permit us to interpret the divergent expressions arising in the perturbation theory of :P(): _d when one does not allow any renormalization besides the usual coupling constants, mass and wave function renormalizations.Supported in part by NSF grant PHY-8342570. Address after March 1985: Theoretische Physik, ETH-Hönggerberg, CH-8093 Zürich, SwitzerlandSupported in part by NSF grant MCS-8108814 (A03)