314 research outputs found
Orbifold Compactification and Solutions of M--Theory from Milne Spaces
In this paper, we consider solutions and spectral functions of M-theory from
Milne spaces with extra free dimensions. Conformal deformations to the metric
associated with the real hyperbolic space forms are derived. For the
three-dimensional case, the orbifold identifications , where is the identity matrix, is analyzed in
detail. The spectrum of a eleven-dimensional field theory can be obtained with
the help of the theory of harmonic functions in the fundamental domain of this
group and it is associated with the cusp forms and the Eisenstein series. The
supersymmetry surviving for supergravity solutions involving real hyperbolic
space factors is briefly discussed.Comment: 14 pages, no figures. To appear in The European Physical Journal C -
Particles and Field
Asymptotic Density of Open p-brane States with Zero-modes included
We obtain the asymptotic density of open p-brane states with zero-modes
included. The resulting logarithmic correction to the p-brane entropy has a
coefficient - \frac{p + 2}{2 p}, and is independent of the dimension of the
embedding spacetime. Such logarithmic corrections to the entropy, with
precisely this coefficient, appear in two other contexts also: a gas of
massless particles in p-dimensional space, and a Schwarzschild black hole in (p
+ 2)-dimensional anti de Sitter spacetime.Comment: 9 pages, Latex. V 2: Results are for open p-branes only; Title
modified; a few references and an acknowledgement adde
Global anomaly and a family of structures on fold product of complex two-cycles
We propose a new set of IIB type and eleven-dimensional supergravity
solutions which consists of the -fold product of two-spaces (where denotes the product of upper half-planes
equipped with the co-compact action of ) and (where and is a congruence subgroup of ). The
Freed-Witten global anomaly condition have been analyzed. We argue that the
torsion part of the cuspidal cohomology involves in the global anomaly
condition. Infinitisimal deformations of generalized complex (and K\"ahler)
structures also has been analyzed and stability theorem in the case of a
discrete subgroup of with the compact quotient was verified.Comment: 7 pages, no figures. To appear in the Proceedings of XXVIII Workshop
on Geometrical Methods in Physics, Bialowieza (Poland), 28.06 - 04.07.200
Quantum States, Thermodynamic Limits and Entropy in M-Theory
We discuss the matching of the BPS part of the spectrum for (super)membrane,
which gives the possibility of getting membrane's results via string
calculations. In the small coupling limit of M--theory the entropy of the
system coincides with the standard entropy of type IIB string theory (including
the logarithmic correction term). The thermodynamic behavior at large coupling
constant is computed by considering M--theory on a manifold with topology
. We argue that the finite temperature
partition functions (brane Laurent series for ) associated with BPS
brane spectrum can be analytically continued to well--defined functionals.
It means that a finite temperature can be introduced in brane theory, which
behaves like finite temperature field theory. In the limit (point
particle limit) it gives rise to the standard behavior of thermodynamic
quantities.Comment: 7 pages, no figures, Revtex style. To be published in the Physical
Review
BRST-Invariant Deformations of Geometric Structures in Sigma Models
We study a Lie algebra of formal vector fields with its application to
the perturbative deformed holomorphic symplectic structure in the A-model, and
a Calabi-Yau manifold with boundaries in the B-model. We show that equivalent
classes of deformations are describing by a Hochschild cohomology theory of the
DG-algebra , ,
which is defined to be the cohomology of . Here
is the initial non-deformed BRST operator while is the deformed part whose algebra is a Lie algebra of linear vector
fields . We show that equivalent classes of deformations are
described by a Hochschild cohomology of , an important geometric
invariant of the (anti)holomorphic structure on . We discuss the
identification of the harmonic structure
of affine space and the group {\rm Ext}_{X^{2}}^n({\cO}_{\triangle},
{\cO}_{\triangle}) (the HKR isomorphism), and bulk-boundary deformation
pairing.Comment: 13 pages, no figure
Thermodynamics of Abelian Gauge Fields in Real Hyperbolic Spaces
We work with dimensional compact real hyperbolic space with
universal covering and fundamental group . Therefore, is the
symmetric space , where and is a maximal compact
subgroup of . We regard as a discrete subgroup of acting
isometrically on , and we take to be the quotient space by that
action: . The natural
Riemannian structure on (therefore on ) induced by the Killing form of
gives rise to a connection form Laplacian on the quotient
vector bundle (associated with an irreducible representation of K). We study
gauge theories based on abelian forms on the real compact hyperbolic
manifold . The spectral zeta function related to the operator
, considering only the co-exact part of the forms and
corresponding to the physical degrees of freedom, can be represented by the
inverse Mellin transform of the heat kernel. The explicit thermodynamic
fuctions related to skew-symmetric tensor fields are obtained by using the
zeta-function regularization and the trace tensor kernel formula (which
includes the identity and hyperbolic orbital integrals). Thermodynamic
quantities in the high and low temperature expansions are calculated and new
entropy/energy ratios established.Comment: Six pages, Revtex4 style, no figures; small typo correcte
Hyperbolic Topological Invariants and the Black Hole Geometry
We discuss the isometry group structure of three-dimensional black holes and
Chern-Simons invariants. Aspects of the holographic principle relevant to black
hole geometry are analyzed.Comment: 11 pages, AMSTeX, Contribution to the Fifth Alexander Friedmann
International Seminar on Gravitation and Cosmolog
Quantum State Density and Critical Temperature in M-theory
We discuss the asymptotic properties of quantum states density for
fundamental branes which can yield a microscopic interpretation of the
thermodynamic quantities in M-theory. The matching of BPS part of spectrum for
superstring and supermembrane gives the possibility of getting membrane's
results via string calculations. In the weak coupling limit of M-theory the
critical behavior coincides with the first order phase transition in standard
string theory at temperature less than the Hagedorn's temperature . The
critical temperature at large coupling constant is computed by considering
M-theory on manifold with topology .
Alternatively we argue that any finite temperature can be introduced in the
framework of membrane thermodynamics.Comment: 16 pages, published in Mod. Phys. Lett. A16(2001)224
- …