530,405 research outputs found
Small cosmological constant in seesaw mechanism with breaking down SUSY
The observed small value of cosmological constant can be naturally related
with the scale of breaking down supersymmetry in agreement with other
evaluations in particle physics.Comment: 12 pages, revtex4 class, 2 eps-figure
Hamilton-Jacobi quantization of singular Lagrangians with linear velocities
In this paper, constrained Hamiltonian systems with linear velocities are
investigated by using the Hamilton-Jacobi method. We shall consider the
integrablity conditions on the equations of motion and the action function as
well in order to obtain the path integral quantization of singular Lagrangians
with linear velocities.Comment: late
Nonlinearly Realized Extended Supergravity
We provide nonlinear realization of supergravity with an arbitrary number of
supersymmetries by means of coset construction. The number of gravitino degrees
of freedom counts the number of supersymmetries, which will be possibly probed
in future experiments. We also consider goldstino embedding in the construction
to discuss the relation to nonlinear realization with rigid supersymmetries.Comment: 19 page
Brane-Induced Gravity's Shocks
We construct exact gravitational field solutions for a relativistic particle
localized on a tensional brane in brane-induced gravity. They are a
generalization of gravitational shock waves in 4D de Sitter space. We provide
the metrics for both the normal branch and the self-inflating branch DGP
braneworlds, and compare them to the 4D Einstein gravity solution and to the
case when gravity resides only in the 5D bulk, without any brane-localized
curvature terms. At short distances the wave profile looks the same as in four
dimensions. The corrections appear only far from the source, where they differ
from the long distance corrections in 4D de Sitter space. We also discover a
new non-perturbative channel for energy emission into the bulk from the
self-inflating branch, when gravity is modified at the de Sitter radius.Comment: 4 pages, revtex4; v4: a sign error corrected; the correction
tantamount to swapping normal and self-inflating branch solutions; the only
significant change is that the spectacular new instability is on the
self-inflating branch in the limit of vanishing brane tension; more details
available in hep-th/050203
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