9,457 research outputs found
Affine crystal structure on rigged configurations of type D_n^(1)
Extending the work arXiv:math/0508107, we introduce the affine crystal action
on rigged configurations which is isomorphic to the Kirillov-Reshetikhin
crystal B^{r,s} of type D_n^(1) for any r,s. We also introduce a representation
of B^{r,s} (r not equal to n-1,n) in terms of tableaux of rectangular shape r x
s, which we coin Kirillov-Reshetikhin tableaux (using a non-trivial analogue of
the type A column splitting procedure) to construct a bijection between
elements of a tensor product of Kirillov-Reshetikhin crystals and rigged
configurations.Comment: 26 pages, 3 figures. (v3) corrections in the proof reading. (v2) 26
pages; examples added; introduction revised; final version. (v1) 24 page
Saddle index properties, singular topology, and its relation to thermodynamical singularities for a phi^4 mean field model
We investigate the potential energy surface of a phi^4 model with infinite
range interactions. All stationary points can be uniquely characterized by
three real numbers $\alpha_+, alpha_0, alpha_- with alpha_+ + alpha_0 + alpha_-
= 1, provided that the interaction strength mu is smaller than a critical
value. The saddle index n_s is equal to alpha_0 and its distribution function
has a maximum at n_s^max = 1/3. The density p(e) of stationary points with
energy per particle e, as well as the Euler characteristic chi(e), are singular
at a critical energy e_c(mu), if the external field H is zero. However, e_c(mu)
\neq upsilon_c(mu), where upsilon_c(mu) is the mean potential energy per
particle at the thermodynamic phase transition point T_c. This proves that
previous claims that the topological and thermodynamic transition points
coincide is not valid, in general. Both types of singularities disappear for H
\neq 0. The average saddle index bar{n}_s as function of e decreases
monotonically with e and vanishes at the ground state energy, only. In
contrast, the saddle index n_s as function of the average energy bar{e}(n_s) is
given by n_s(bar{e}) = 1+4bar{e} (for H=0) that vanishes at bar{e} = -1/4 >
upsilon_0, the ground state energy.Comment: 9 PR pages, 6 figure
Observation of a first-order phase transition deep within the vortex-solid region of YBa2Cu3O7
We have investigated the magnetic phase diagram of a fully oxygenated
detwinned YBa2Cu3O7 single crystal by means of magneto-caloric and
magnetization measurements, and found thermodynamic evidence for a temperature
dependent first-order phase-transition line deep within the vortex-solid
region. The associated discontinuities in the entropy are apparently
proportional to the magnetic flux density, which may hint at a structural
transition of the vortex lattice
Microscopic Dynamics of Hard Ellipsoids in their Liquid and Glassy Phase
To investigate the influence of orientational degrees of freedom onto the
dynamics of molecular systems in its supercooled and glassy regime we have
solved numerically the mode-coupling equations for hard ellipsoids of
revolution. For a wide range of volume fractions and aspect ratios
we find an orientational peak in the center of mass spectra
and about one decade
below a high frequency peak. This orientational peak is the counterpart of a
peak appearing in the quadrupolar spectra and
. The latter peak is almost insensitive on
for close to one, i.e. for weak steric hindrance, and broadens strongly
with increasing . Deep in the glass we find an additional peak between
the orientational and the high frequency peak. We have evidence that this
intermediate peak is the result of a coupling between modes with and
, due to the nondiagonality of the static correlators.Comment: 6 figures, 12 page
Macroporous silicon membranes as electron and x-ray transmissive windows
Macroporous silicon membranes are fabricated whose pores are terminated with 60 nm thin silicon dioxide shells. The transmission of electrons with energies of 5 kV-25 kV through these membranes was investigated reaching a maximum of 22% for 25 kV. Furthermore, the transmission of electromagnetic radiation ranging from the far-infrared to the x-ray region was determined. The results suggest the application of the membrane as window material for electron optics and energy dispersive x-ray detectors
Bailey flows and Bose-Fermi identities for the conformal coset models
We use the recently established higher-level Bailey lemma and Bose-Fermi
polynomial identities for the minimal models to demonstrate the
existence of a Bailey flow from to the coset models
where is a
positive integer and is fractional, and to obtain Bose-Fermi identities
for these models. The fermionic side of these identities is expressed in terms
of the fractional-level Cartan matrix introduced in the study of .
Relations between Bailey and renormalization group flow are discussed.Comment: 28 pages, AMS-Latex, two references adde
Dynamical precursor of nematic order in a dense fluid of hard ellipsoids of revolution
We investigate hard ellipsoids of revolution in a parameter regime where no
long range nematic order is present but already finite size domains are formed
which show orientational order. Domain formation leads to a substantial slowing
down of a collective rotational mode which separates well from the usual
microscopic frequency regime. A dynamic coupling of this particular mode into
all other modes provides a general mechanism which explains an excess peak in
spectra of molecular fluids. Using molecular dynamics simulation on up to 4096
particles and on solving the molecular mode coupling equation we investigate
dynamic properties of the peak and prove its orientational origin.Comment: RevTeX4 style, 7 figure
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