19 research outputs found
BPS Solutions in D=5 Dilaton-Axion Gravity
We show that the D=5 dilaton-axion gravity compactified on a 2-torus
possesses the SL(4,R)/SO(4) matrix formulation. It is used for construction of
the SO(2,2)-invariant BPS solution depended on the one harmonic function.Comment: presented at GR1
Symplectic Gravity Models in Four, Three and Two Dimensions
A class of the gravity models describing a coupled system of
Abelian vector fields and the symmetric matrix generalizations of
the dilaton and Kalb-Ramond fields is considered. It is shown that the
Pecci-Quinn axion matrix can be entered and the resulting equations of motion
possess the symmetry in four dimensions. The stationary case is
studied. It is established that the theory allows a -model
representation with a target space which is invariant under the
group of isometry transformations. The chiral matrix of the coset is constructed. A K\"ahler formalism based on the use of the Ernst
complex symmetric matrix is developed. The stationary
axisymmetric case is considered. The Belinsky-Zakharov chiral matrix depending
on the original field variables is obtained. The Kramer-Neugebauer
transformation, which algebraically maps the original variables into the target
space ones, is presented.Comment: 21 pages, RevTex, no figurie
Sp(4,R)/GL(2,R) Matrix Structure of Geodesic Solutions for Einstein--Maxwell--Dilaton--Axion Theory
The constructed matrix operator defines the family of
isotropic geodesic containing vacuum point lines in the target space of the
stationary D=4 Einstein--Maxwell--dilaton--axion theory. This operator is used
to derive a class of solutions which describes a point center system with
nontrivial values of mass, parameter NUT, as well as electric, magnetic,
dilaton and axion charges. It is shown that this class contains both particular
solutions Majumdar--Papapetrou--like black holes and massless asymptotically
nonflat naked singularities.Comment: 20 pages, RevTex, no figures, Submitted to Phys.Rev.
Kramer--Neugebauer Transformation for Einstein--Maxwell--Dilaton--Axion Theory
The Kramer--Neugebauer--like transformation is constructed for the stationary
axisymmetric D=4 Einstein--Maxwell--dilaton--axion system. This transformation
directly maps the dualized sigma--model equations of the theory into the
nondualized ones. Also the new chiral matrix representation of the
problem is presented.Comment: 13 pages, RevTex, no figure
Chiral models in dilaton-Maxwell gravity
We study symmetry properties of the Einstein-Maxwell theory nonminimaly
coupled to the dilaton field. We consider a static case with pure electric
(magnetic) Maxwell field and show that the resulting system becomes a nonlinear
sigma-model wich possesses a chiral representation. We construct the
corresponding chiral matrix and establish a representation which is related to
the pair of Ernst-like potentials. These potentials are used for separation of
the symmetry group into the gauge and nongauge (charging) sectors. New
variables, which linearize the action of charging symmetries, are also
established; a solution generation technique based on the use of charging
symmetries is formulated. This technique is used for generation of the
elecricaly (magneticaly) charged dilatonic fields from the static General
Relativity ones.Comment: 9 pages in LaTex; published in Gen. Rel. Grav. 32 (2000) pp 1389-139
U(1,1)--Invariant Generation of Charges for Einstein--Maxwell--Dilaton--Axion Theory
The action of the isometry subgroup which preserves the trivial values of the
fields is studied for the stationary D=4 Einstein--Maxwell--Dilaton--Axion
theory. The technique for generation of charges and the corresponding procedure
for construction of new solutions is formulated. A solution describing the
double rotating dyon with independent values of all physical charges is
presented.Comment: 14 pages, RevTex, no figurie
Soliton solution in dilaton-Maxwell gravity
The inverse scattering problem method application to construction of exact
solution for Maxwell dilaton gravity system ia considered. By use of Belinsky
and Zakharov L - A pair the solution of the theory is constructed. The rotating
Kerr - like configuration with NUT - parameter is obtained.Comment: 8 pages in LaTex; published in Gen. Rel. Grav. pp. 32 (2000)
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