98,099 research outputs found
Dilaton - fixed scalar correlators and AdS_5 x S^5 - SYM correspondence
We address the question of AdS/CFT correspondence in the case of the 3-point
function . O_4 and O_8 are particular primary states represented
by F^2 + ... and F^4 + ... operators in \N=4 SYM theory and dilaton \phi and
massive `fixed' scalar \nu in D=5 supergravity. While the value of <O_4 O_4
O_8> computed in large N weakly coupled SYM theory is non-vanishing, the D=5
action of type IIB supergravity compactified on S^5 does not contain
\phi\phi\nu coupling and thus the corresponding correlator seems to vanish on
the AdS_5 side. This is in obvious contradiction with arguments suggesting
non-renormalization of 2- and 3-point functions of states from short multiplets
and implying agreement between the supergravity and SYM expressions for them.
We propose a natural resolution of this paradox which emphasizes the
10-dimensional nature of the correspondence. The basic idea is to treat the
constant mode of the dilaton as a part of the full S^5 Kaluza-Klein family of
dilaton modes. This leads to a non-zero result for the correlator
on the supergravity side.Comment: 16 pages, harvmac; references adde
BRST invariance and de Rham-type cohomology of 't Hooft-Polyakov monopole
We exploit the 't Hooft-Polyakov monopole to define closed algebra of the
quantum field operators and the BRST charge . In the first-class
configuration of the Dirac quantization, by including the -exact
gauge fixing term and the Faddeev-Popov ghost term, we find the BRST invariant
Hamiltonian to investigate the de Rham-type cohomology group structure for the
monopole system. The Bogomol'nyi bound is also discussed in terms of the
first-class topological charge defined on the extended internal 2-sphere.Comment: 8 page
Fragile Mott Insulators
We prove that there exists a class of crystalline insulators, which we call
"fragile Mott insulators" which are not adiabatically connected to any sort of
band insulator provided time-reversal and certain point-group symmetries are
respected, but which are otherwise unspectacular in that they exhibit no
topological order nor any form of fractionalized quasiparticles. Different
fragile Mott insulators are characterized by different nontrivial
one-dimensional representations of the crystal point group. We illustrate this
new type of insulators with two examples: the d-Mott insulator discovered in
the checkerboard Hubbard model at half-filling and the
Affleck-Kennedy-Lieb-Tasaki insulator on the square lattice.Comment: 4 pages, 2 figures. Published version in PRL. The name "Weak Mott
Insulators" is changed to "Fragile Mott Insulators" to avoid confusing in
terminolog
An exact chiral spin liquid with non-Abelian anyons
We establish the existence of a chiral spin liquid (CSL) as the exact ground
state of the Kitaev model on a decorated honeycomb lattice, which is obtained
by replacing each site in the familiar honeycomb lattice with a triangle. The
CSL state spontaneously breaks time reversal symmetry but preserves other
symmetries. There are two topologically distinct CSLs separated by a quantum
critical point. Interestingly, vortex excitations in the topologically
nontrivial (Chern number ) CSL obey non-Abelian statistics.Comment: 4 pages, 2 figures; published version in Phys. Rev. Let
Neutron Removal from the Deformed Halo 31Ne Nucleus
Experimental data on Coulomb breakup and neutron removal indicate that 31Ne
is one of the heaviest halo nuclei discovered so far. The possible ground state
of 31Ne is either 3/2- coming from p-wave halo or 1/2+ from s-wave halo. In
this work, we develop a treatable model to include deformed wave functions and
a dynamical knockout formalism which includes the dependence on the nuclear
orientation to study the neutron removal from 31Ne projectiles at energies
around E=200 MeV/nucleon. A detailed account of the effects of deformation on
cross sections and longitudinal momentum distributions is made. Our numerical
analysis indicates a preference for the 31Ne ground state with spin parity
3/2-.Comment: 22 pages, 13 figures, accepted for publication in the Physical Review
Controlling the Size of Popcorn
We present a thermo-statistical model of popcorn production and propose a way
to control the final size of the popcorn by monitoring only the chamber
pressure.Comment: 6 pages; revision (typo and minor content corrections
Density Functional Theory of Hard Sphere Condensation Under Gravity
The onset of condensation of hard spheres in a gravitational field is studied
using density functional theory. In particular, we find that the local density
approximation yields results identical to those obtained previously using the
kinetic theory [Physica A 271, 192, (1999)], and a weighted density functional
theory gives qualitatively similar results, namely, that the temperature at
which condensation begins at the bottom scales linearly with weight, diameter,
and number of layers of particles.Comment: 17 pages, 4 figure
Three new species of Helicopsyche (Trichoptera, Helicopsychidae) from northern Vietnam, with a key to Helicopsyche species of Vietnam
Three new species of Helicopsyche Siebold, 1856 are described from Vietnam: Helicopsyche melina sp. nov., Helicopsyche meander sp. nov., and Helicopsyche lamnata sp. nov. All species were described from Melinh Station for Biodiversity in the Me Linh District of Vinh Phuc Province. The species were collected mainly in Malaise traps situated across a small stream surrounded by lowland forest. Some individuals were also collected on light in traps situated at the stream bank
model with Hopf term and fractional spin statistics
We reconsider the model with the Hopf term by using the
Batalin-Fradkin-Tyutin (BFT) scheme, which is an improved version of the Dirac
quantization method. We also perform a semi-classical quantization of the
topological charge Q sector by exploiting the collective coordinates to
explicitly show the fractional spin statistics.Comment: 15 page
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