83,774 research outputs found
Feminism in philosophy of language: communicative speech acts
Book synopsis:
The thirteen specially-commissioned essays in this volume are written by philosophers at the forefront of feminist scholarship, and are designed to provide an accessible and stimulating guide to a philosophical literature that has seen massive expansion in recent years. Ranging from history of philosophy through metaphysics to philosophy of science, they encompass all the core subject areas commonly taught in anglophone undergraduate and graduate philosophy courses, offering both an overview of and a contribution to the relevant debates. Together they testify to the intellectual value of feminism as a radicalizing energy internal to philosophical inquiry. This volume will be essential reading for any student or teacher of philosophy who is curious about the place of feminism in their subject
Low-energy fusion caused by an interference
Fusion of two deuterons of room temperature energy is studied. The nuclei are
in vacuum with no connection to any external source (electric or magnetic
field, illumination, surrounding matter, traps, etc.) which may accelerate
them. The energy of the two nuclei is conserved and remains small during the
motion through the Coulomb barrier. The penetration through this barrier, which
is the main obstacle for low-energy fusion, strongly depends on a form of the
incident flux on the Coulomb center at large distances from it. In contrast to
the usual scattering, the incident wave is not a single plane wave but the
certain superposition of plane waves of the same energy and various directions,
for example, a convergent conical wave. As a result of interference, the wave
function close to the Coulomb center is determined by a cusp caustic which is
probed by de Broglie waves. The particle flux gets away from the cusp and moves
to the Coulomb center providing a not small probability of fusion (cusp driven
tunneling). Getting away from a caustic cusp also occurs in optics and
acoustics
Large time asymptotics for the fluctuation SPDE in the Kuramoto synchronization model
We investigate the long-time asymptotics of the fluctuation SPDE in the
Kuramoto synchronization model. We establish the linear behavior for large time
and weak disorder of the quenched limit fluctuations of the empirical measure
of the particles around its McKean-Vlasov limit. This is carried out through a
spectral analysis of the underlying unbounded evolution operator, using
arguments of perturbation of self-adjoint operators and analytic semigroups. We
state in particular a Jordan decomposition of the evolution operator which is
the key point in order to show that the fluctuations of the disordered Kuramoto
model are not self-averaging.Comment: 34 pages, 5 figures; V2: introduction simplified, references added
and typos correcte
Multipartite quantum nonlocality under local decoherence
We study the nonlocal properties of two-qubit maximally-entangled and N-qubit
Greenberger-Horne-Zeilinger states under local decoherence. We show that the
(non)resilience of entanglement under local depolarization or dephasing is not
necessarily equivalent to the (non)resilience of Bell-inequality violations.
Apart from entanglement and Bell-inequality violations, we consider also
nonlocality as quantified by the nonlocal content of correlations, and provide
several examples of anomalous behaviors, both in the bipartite and multipartite
cases. In addition, we study the practical implications of these anomalies on
the usefulness of noisy Greenberger-Horne-Zeilinger states as resources for
nonlocality-based physical protocols given by communication complexity
problems. There, we provide examples of quantum gains improving with the number
of particles that coexist with exponentially-decaying entanglement and
non-local contents.Comment: 6 pages, 4 figure
Angular Momentum Transfer in Vela-like Pulsar Glitches
The angular momentum transfer associated to Vela-like glitches has never been
calculated {\em directly} within a realistic scenario for the storage and
release of superfluid vorticity; therefore, the explanation of giant glitches
in terms of vortices has not yet been tested against observations. We present
the first physically reasonable model, both at the microscopic and macroscopic
level (spherical geometry, n=1 polytropic density profile, density-dependent
pinning forces compatible with vortex rigidity), to determine where in the star
the vorticity is pinned, how much of it, and for how long. For standard neutron
star parameters ( km, Hz s), we find that maximum pinning forces of order
dyn cm can accumulate erg s of superfluid angular momentum, and release it to the
crust at intervals years. This estimate of is one order of magnitude smaller than what implied indirectly by
current models for post-glitch recovery, where the core and inner-crust
vortices are taken as physically disconnected; yet, it successfully yields the
magnitudes observed in recent Vela glitches for {\em both} jump parameters,
and , provided one assumes
that only a small fraction () of the total star vorticity is coupled to
the crust on the short timescale of a glitch. This is reasonable in our
approach, where no layer of normal matter exists between the core and the
inner-crust, as indicated by existing microscopic calculation. The new scenario
presented here is nonetheless compatible with current post-glitch models.Comment: 11 pages, 4 figure
Evolution of a metastable phase with a magnetic phase coexistence phenomenon and its unusual sensitivity to magnetic field cycling in the alloys Tb5-xLuxSi3 (x <= 0.7)
Recently, we reported an anomalous enhancement of the positive
magnetoresistance beyond a critical magnetic field in Tb5Si3 in the
magnetically ordered state, attributable to 'inverse metamagnetism'. This
results in unusual magnetic hysteresis loops for the pressurized specimens,
which are relevant to the topic of 'electronic phase separation'. In this
paper, we report the influence of small substitutions of Lu for Tb, to show the
evolution of these magnetic anomalies. We find that, at low temperatures, the
high-field high-resistivity phase could be partially stabilized on returning
the magnetic field to zero in many of these Lu substituted alloys, as measured
through the electrical resistivity ({\rho}). Also, the relative fractions of
this phase and the virgin phase appear to be controlled by a small tuning of
the composition and temperature. Interestingly, at 1.8 K a sudden 'switch-over'
of the value of {\rho} for this mixed phase to that for the virgin phase for
some compositions is observed at low fields after a few field cycles,
indicating metastability of this mixed phase
Majorana fermions emerging from magnetic nanoparticles on a superconductor without spin-orbit coupling
There exists a variety of proposals to transform a conventional s-wave
superconductor into a topological superconductor, supporting Majorana fermion
mid-gap states. A necessary ingredient of these proposals is strong spin-orbit
coupling. Here we propose an alternative system consisting of a one-dimensional
chain of magnetic nanoparticles on a superconducting substrate. No spin-orbit
coupling in the superconductor is needed. We calculate the topological quantum
number of a chain of finite length, including the competing effects of disorder
in the orientation of the magnetic moments and in the hopping energies, to
identify the transition into the topologically nontrivial state (with Majorana
fermions at the end points of the chain).Comment: 7 pages, 5 figure
KxFe2-ySe2 single crystals: Floating-zone growth, Transport and Structural properties
Single crystals of superconducting KxFe2-ySe2 have been grown with the
optical floating-zone technique under application of 8 bar of argon pressure.
We found that large and high quality single crystals with dimensions of
~\varnothing6 \times 10 mm could be obtained at the termination of the grown
ingot through quenching, while the remaining part of the ingot decomposed.
As-grown single crystals commonly represent an intergrowth of two sets of the
c-axis characterized by slightly different lattice constants. Single crystal of
K0.80Fe1.81Se2 shows a superconducting transition at Tc = 31.6 K, leading to a
near 100% expulsion of the external magnetic field in magnetization
measurements. On the other hand, neutron-diffraction data indicate that
superconductivity in the sample coexists with a iron-vacancy superstructure and
static antiferromagnetic order. The anisotropic ratio of the upper critical
field Hc2 for both H//c and H//ab configurations is \sim3.46
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