21,750 research outputs found
Statements of Interest: Addendum to the Testimony of 9 To 5, the National Association of Working Women, et al. Before the Commission on the Future of Worker-Management Relations
Addendum_Lichtman_et_al_040694.pdf: 179 downloads, before Oct. 1, 2020
Spinning Solitons of a Modified Non-Linear Schroedinger equation
We study soliton solutions of a modified non-linear Schroedinger (MNLS)
equation. Using an Ansatz for the time and azimuthal angle dependence
previously considered in the studies of the spinning Q-balls, we construct
multi-node solutions of MNLS as well as spinning generalisations.Comment: 8 Revtex pages, 5 ps figures; v2: minor change
Light-shift-induced photonic nonlinearities
We propose a new method to produce self- and cross-Kerr photonic
nonlinearities, using light-induced Stark shifts due to the interaction of a
cavity mode with atoms. The proposed experimental set-up is considerably
simpler than in previous approaches, while the strength of the nonlinearity
obtained with a single atom is the same as in the setting based on
electromagnetically induced transparency. Furthermore our scheme can be applied
to engineer effective photonic nonlinear interactions whose strength increases
with the number of atoms coupled to the cavity mode, leading to photon-photon
interactions several orders of magnitude larger than previously considered
possible.Comment: 4 pages, 4 figure
Quantum phase transitions with Photons and Polaritons
We show that a system of polaritons - combined atom and photon excitations -
in an array of coupled cavities, under an experimental set-up usually
considered in electromagnetically induced transparency, is described by the
Bose-Hubbard model. This opens up the possibility of using this system as a
quantum simulator, allowing for the observation of quantum phase transitions
and for the measurement of local properties, such as single site observables.
All the basic building blocks of the proposed setting have already been
achieved experimentally, showing the feasibility of its realization in the near
future.Comment: 7 pages, contribution for the proceedings of the QCMC0
Coordinated IUE, Einstein and optical observations of accreting degenerate dwarfs
Three binary systems believed to be composed of a white dwarf and a late type star, AM Her, SS Cyg, and U Gem were observed simultaneously in the IV X-ray and optical wavelengths. The system AM Her was in its customary high state at the time of the observations, while SS Cyg and U Gem were in a low state. In all three cases, a significant UV black body component with KT approximately greater than 10 eV was found. The flux in this component is in excess of the amount predicted by current scenarios of gravitational energy release
Renormalization algorithm with graph enhancement
We introduce a class of variational states to describe quantum many-body
systems. This class generalizes matrix product states which underly the
density-matrix renormalization group approach by combining them with weighted
graph states. States within this class may (i) possess arbitrarily long-ranged
two-point correlations, (ii) exhibit an arbitrary degree of block entanglement
entropy up to a volume law, (iii) may be taken translationally invariant, while
at the same time (iv) local properties and two-point correlations can be
computed efficiently. This new variational class of states can be thought of as
being prepared from matrix product states, followed by commuting unitaries on
arbitrary constituents, hence truly generalizing both matrix product and
weighted graph states. We use this class of states to formulate a
renormalization algorithm with graph enhancement (RAGE) and present numerical
examples demonstrating that improvements over density-matrix renormalization
group simulations can be achieved in the simulation of ground states and
quantum algorithms. Further generalizations, e.g., to higher spatial
dimensions, are outlined.Comment: 4 pages, 1 figur
Boson and neutron stars with increased density
We discuss boson stars and neutron stars, respectively, in a scalar-tensor
gravity model with an explicitly time-dependent real scalar field. While the
boson stars in our model -- in contrast to the neutron stars -- do not possess
a hard core, we find that the qualitative effects of the formation of scalar
hair are similar in both cases : the presence of the gravity scalar allows both
type of stars to exist for larger central density as well as larger mass at
given radius than their General Relativity counterparts. In particular, we find
new types of neutron stars with scalar hair which have radii very close to the
corresponding Schwarzschild radius and hence are comparable in density to black
holes. This new branch of solutions is stable with respect to the decay into
individual baryons.Comment: Matches version published in Phys. Lett.
Interpolation and harmonic majorants in big Hardy-Orlicz spaces
Free interpolation in Hardy spaces is caracterized by the well-known Carleson
condition. The result extends to Hardy-Orlicz spaces contained in the scale of
classical Hardy spaces , . For the Smirnov and the Nevanlinna
classes, interpolating sequences have been characterized in a recent paper in
terms of the existence of harmonic majorants (quasi-bounded in the case of the
Smirnov class). Since the Smirnov class can be regarded as the union over all
Hardy-Orlicz spaces associated with a so-called strongly convex function, it is
natural to ask how the condition changes from the Carleson condition in
classical Hardy spaces to harmonic majorants in the Smirnov class. The aim of
this paper is to narrow down this gap from the Smirnov class to ``big''
Hardy-Orlicz spaces. More precisely, we characterize interpolating sequences
for a class of Hardy-Orlicz spaces that carry an algebraic structure and that
are strictly bigger than . It turns out that the
interpolating sequences are again characterized by the existence of
quasi-bounded majorants, but now the weights of the majorants have to be in
suitable Orlicz spaces. The existence of harmonic majorants in such Orlicz
spaces will also be discussed in the general situation. We finish the paper
with an example of a separated Blaschke sequence that is interpolating for
certain Hardy-Orlicz spaces without being interpolating for slightly smaller
ones.Comment: 19 pages, 2 figure
Anomalous latent heat in non-equilibrium phase transitions
We study first-order phase transitions in a two-temperature system, where due
to the time-scale separation all the basic thermodynamical quantities (free
energy, entropy, etc) are well-defined. The sign of the latent heat is found to
be counterintuitive: it is positive when going from the phase where the
temperatures and the entropy are higher to the one where these quantities are
lower. The effect exists only out of equilibrium and requires conflicting
interactions. It is displayed on a lattice gas model of ferromagnetically
interacting spin-1/2 particles.Comment: 4 pages, 2 figure
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