68,421 research outputs found
Uniqueness of Lagrangian Self-Expanders
We show that zero-Maslov class Lagrangian self-expanders in C^n which are
asymptotic to a pair of planes intersecting transversely are locally unique if
n>2 and unique if n=2.Comment: 32 page
On the Stability of Randall-Sundrum Braneworlds with Conformal Bulk Fields
In the Randall-Sundrum scenario we consider exact 5-dimensional solutions
with localized gravity which are associated with a well defined class of
conformal bulk fields. We analyze their behaviour under radion field
perturbations. We show that if the Randall-Sundrum exponential warp is the
localizing metric function and the equation of state of the conformal fields is
not changed by the radion perturbation then the 5-dimensional solutions are
unstable. We present new stable solutions which describe on the brane the
dynamics of inhomogeneous dust, generalized dark radiation and homogeneous
polytopic matter.Comment: 10 pages, latex, no figures. Contribution to the special issue of
Vestnik of Tomsk State Pedagogical University in the field
QFT/Cosmology/Gravity/Strings, edited by Sergei D. Odintso
Braneworlds, Conformal Fields and Dark Energy
In the Randall-Sundrum scenario we analize the dynamics of a spherically
symmetric 3-brane when matter fields propagate in the bulk. For a well defined
class of conformal fields of weight -4 we determine a new set of exact
5-dimensional solutions which localize gravity in the vicinity of the brane and
are stable under radion field perturbations. Geometries which describe the
dynamics of inhomogeneous dust, generalized dark radiation and homogeneous
polytropic dark energy are shown to belong to this set.Comment: 7 pages, latex, no figures. Talk given at the Fifth International
Workshop on New Worlds in Astroparticle Physics, University of Algarve, Faro,
8-10 January 2005. To be published in the workshop proceeding
Braneworlds, Conformal Fields and the Gravitons
We investigate the dynamics of Randall-Sundrum AdS5 braneworlds with
5-dimensional conformal matter fields. In the scenario with a compact fifth
dimension the class of conformal fields with weight -4 is associated with exact
5-dimensional warped geometries which are stable under radion field
perturbations and describe on the brane the dynamics of inhomogeneous dust,
generalized dark radiation and homogeneous polytropic dark energy. We analyse
the graviton mode flutuations around this class of background solutions and
determine their mass eigenvalues and wavefunctions from a Sturm-Liouville
problem. We show that the localization of gravity is not sharp enough for large
mass hierarchies to be generated. We also discuss the physical bounds imposed
by experiments in particle physics, in astrophysics and in precise measurements
of the low energy gravitational interaction.Comment: LaTeX, 9 pages, 2 figures. Based on talk given in the Second
International Conference on Quantum Theories and the Renormalization Group in
Gravity and Cosmology, CSIC and University of Barcelona, Barcelona, Spain,
11-15 July 2006. Submitted to be published in the Conference Proceedings, J.
Phys. A: Math. Ge
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