17,241 research outputs found
Gravity and the Newtonian limit in the Randall-Sundrum model
We point out that the gravitational evolution equations in the
Randall-Sundrum model appear in a different form than hitherto assumed. As a
consequence, the model yields a correct Newtonian limit in a novel manner.Comment: 9 pages, LaTeX, sign changed and references added. We have also
appended a remark on the compatibility of the 4D Poincare invariant metric of
Randall and Sundrum with the boundary equation
Flory Exponents from a Self-Consistent Renormalization Group
The wandering exponent for an isotropic polymer is predicted remarkably
well by a simple argument due to Flory. By considering oriented polymers living
in a one-parameter family of background tangent fields, we are able to relate
the wandering exponent to the exponent in the background field through an
-expansion. We then choose the background field to have the same
correlations as the individual polymer, thus self-consistently solving for
. We find for and for , which is
exactly the Flory result.Comment: 11 pages, Plain Tex (macros included), IASSNS-HEP-93/1
Smectic Order in Double-Twist Cylinders
I propose a double-twist texture with local smectic order, which may have
been seen in recent experiments. As in the Renn-Lubensky TGB phase, the smectic
order is broken only through a lattice of screw dislocations. A melted lattice
of screw dislocations can produce a double-twist texture as can an unmelted
lattice. In the latter case I show that geometry only allows for certain angles
between smectic regions. I discuss the possibility of connecting these
double-twist tubes together to form a smectic blue phase.Comment: 12 pages, plain TeX (macros included), 5 postscript figures
(included). Revised version has some more text and a new figure. To appear in
J. Phys. II France (1997
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