13,930 research outputs found
Three types of superpotentials for perturbations in the Einstein-Gauss-Bonnet gravity
Superpotentials (antisymmetric tensor densities) in Einstein-Gauss-Bonnet
(EGB) gravity for arbitrary types of perturbations on arbitrary curved
backgrounds are constructed. As a basis, the generalized conservation laws in
the framework of an arbitrary D-dimensional metric theory, where conserved
currents are expressed through divergences of superpotentials, are used. Such a
derivation is exact (perturbations are not infinitesimal) and is approached,
when a one solution (dynamical) is considered as a perturbed system with
respect to another solution (background). Three known prescriptions are
elaborated: these are the canonical N{\oe}ther theorem, the Belinfante
symmetrization rule and the field-theoretical derivation. All the three
approaches are presented in an unique way convenient for comparisons and a
development. Exact expressions for the 01-component of the three types of the
superpotentials are derived in the case, when an arbitrary static
Schwarzschild-like solution in the EGB gravity is considered as a perturbed
system with respect to a background of the same type. These formulae are used
for calculating the mass of the Schwarzschild-anti-de Sitter black hole in the
EGB gravity. As a background both the anti-de Sitter spacetime in arbitrary
dimensions and a not maximally symmetric "mass gap" vacuum in 5 dimensions are
considered. Problems and perspectives for a future development, including the
Lovelock gravity, are discussed.Comment: Erratum, where the canonical superpotential and correspondent
formulae are corrected, is adde
A point mass and continuous collapse to a point mass in general relativity
An original way of presentation of the Schwarzschild black hole in the form
of a point-like mass with making the use of the Dirac -function,
including a description of a continuous collapse to such a point mass, is
given. A maximally generalized description restricted by physically reasonable
requirements is developed. A so-called field-theoretical formulation of general
relativity, being equivalent to the standard geometrical presentation of
general relativity, is used. All of the dynamical fields, including the
gravitational field, are considered as propagating in a background (curved or
flat) spacetime. Namely these properties allow us to present a
non-contradictive picture of the point mass description. The results can be
useful for studying the structure of the black hole true singularities and
could be developed for practical calculations in models with black holes.Comment: 25 pages. arXiv admin note: text overlap with arXiv:gr-qc/0410041 by
other author
AC Stark effect in ThO for the electron EDM search
A method and code for calculations of diatomic molecules in the external
variable electromagnetic field have been developed. Code applied for
calculation of systematics in the electron's electric dipole moment search
experiment on ThO state related to geometric phases, including
dependence on -doublet, rotational level, and external static electric
field. It is found that systematics decrease cubically with respect to the
frequency of the rotating transverse component of the electric field.
Calculation confirms that experiment on ThO state is very robust
against systematic errors related to geometric phases.Comment: 4 page
Field-theoretical construction of currents and superpotentials in Lovelock gravity
Conserved currents and related superpotentials for perturbations on arbitrary
backgrounds in the Lovelock theory are constructed. We use the Lagrangian based
field-theoretical method where perturbations are considered as dynamical fields
propagating on a given background. Such a formulation is exact (not
approximate) and equivalent to the theory in the original metric form. From the
very start, using Noether theorem, we derive the Noether-Klein identities and
adopt them for the purposes of the current work. Applying these identities in
the framework of Lovelock theory, we construct conserved currents,
energy-momentum tensors out of them, and related superpotentials with arbitrary
displacement vectors, not restricting to Killing vectors. A comparison with the
well known Abbott-Deser-Tekin approach is given. The developed general
formalism is applied to give conserved quantities for perturbations on anti-de
Sitter (AdS) backgrounds. As a test we calculate mass of the Schwarzschild-AdS
black hole in the Lovelock theory in arbitrary dimensions. Proposals for
future applications are presented.Comment: 29 pages, to appear in Class. Quantum Gra
Perturbations in the Einstein theory of gravity: Conserved currents
General relativity in the form where gravitational perturbations together
with other physical fields propagate on an auxiliary background is considered.
With using the Katz-Bi{\v{c}}\'ak-Lynden-Bell technique new conserved currents,
divergences of antisymmetric tensor densities(superpotentials), in an arbitrary
curved spacetime are constructed.Comment: LATEX, 8 page
The Rabi frequency on the to transition in ThO: influence of interaction with electric and magnetic fields
Calculations of the correlations between the Rabi frequency on the
to transition in ThO molecule and experimental setup
parameters in the electron electric dipole moment (eEDM) search experiment is
performed. Calculations are required for estimations of systematic errors in
the experiment due to imperfections in laser beams used to prepare the molecule
and read out the eEDM signal
The field theoretical formulation of general relativity and gravity with non-zero masses of gravitons
It is a review paper. General relativity (GR) is presented in the field
theoretical form, where gravitational field (metric perturbations) together
with other physical fields are propagated in an auxiliary arbitrary curved
background spacetime. Conserved currents are constructed and expressed through
divergences of antisymmetrical tensor densities (superpotentials). This permits
to connect local properties of perturbations with the quasi-local nature of the
conserved quantities in GR. The problem of the non-localization of energy in GR
is presented in exact mathematical expressions. A modification of GR developed
recently by Babak and Grishchuk on the basis of the field formulation of GR is
described. Their theory includes massive of spin-2 and spin-0 gravitons. All
its local weak-field predictions are in agreement with experimental data. The
exact equations of the massive theory eliminate the black hole event horizons
and give an oscillator behavior for the homogeneous isotropic universe.Comment: LaTeX, 18 pages, no figures. It is a translation with very minor
changes of the invited paper to the Russian book referred below. A compressed
version of the paper is in the 2-nd volume of the Proceedings to PIRT-IX,
London: 3-6 September, 2004, p.p. 433-44
Restoration of Many Electron Wave Functions from One-Electron Density
General theorem describing a relation between diagonal of one-electron
density matrix and a certain class of many-electron ensembles of determinant
states is proved. As a corollary to this theorem a constructive proof of
sufficiency of Coleman's representability conditions is obtained. It is shown
that there exist rigorous schemes for construction of energy of many-electron
system as functionals of one-electron density.Comment: LaTex, 10 page
Conservation Laws for Large Perturbations on Curved Backgrounds
Backgrounds are pervasive in almost every application of general relativity.
Here we consider the Lagrangian formulation of general relativity for large
perturbations with respect to a curved background spacetime. We show that
Noether's theorem combined with Belinfante's "symmetrization" method applied to
the group of displacements provide a conserved vector, a "superpotential" and a
energy-momentum that are independent of any divergence added to the Hilbert
Lagrangian of the perturbations. The energy-momentum is symmetrical and
divergenceless only on backgrounds that are Einstein spaces in the sense of
A.Z.Petrov.Comment: 13 pages, LaTeX, to appear in the Proceedings of the Conference on
"Fundamental Interactions: From Symmetries to Black Holes" held in Brussels
March 25 - 27, 199
Accurate calculations of the dissociation energy, equilibrium distance and spectroscopic constants for the Yb dimer
The dissociation energy, equilibrium distance, and spectroscopic constants
for the ground state of the Yb molecule are calculated. The
relativistic effects are introduced through generalized relativistic effective
core potentials with very high precision. The scalar relativistic coupled
cluster method particularly well suited for closed-shell van-der-Waals systems
is used for the correlation treatment. Extensive generalized correlation basis
sets were constructed and employed. The relatively small corrections for
high-order cluster amplitudes and spin-orbit interactions are taken into
account using smaller basis sets and the spin-orbit density functional theory.Comment: 10 pages, 3 tables, 1 figure (the paper was extended
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