11,654 research outputs found
Pairing properties of the inner crust of neutron stars at finite temperature
We investigate the thermal properties of the inner crust of a neutron star
using the Hartree-Fock-Bogoliubov (HFB) formalism at finite temperature. We
compare our results with the ones obtained solving the same equations, but
within the BCS approximation. We observe that for the outermost regions of the
inner crust, the two methods can show important differences, in particular when
we use them to calculate the neutron specific heat of the system
Pairing properties and specific heat of the inner crust of a neutron star
We investigate the pairing properties at finite temperature of the
Wigner-Seitz cells in the inner crust of a neutron star obtained with the
recent Brussels-Montreal Skyrme functional BSk21. In particular we analyze the
phenomena of persistence and reentrance of pairing correlations and their
impact on the specific heat in the low-density region of the inner crust.Comment: Submitted to Phys. Rev.
Generating functionals, consistency, and uniqueness in the integral equation theory of liquids
We discuss and illustrate through numerical examples the relations between
generating functionals, thermodynamic consistency (in particular the
virial-free energy one), and uniqueness of the solution, in the integral
equation theory of liquids. We propose a new approach for deriving closures
automatically satisfying such characteristics. Results from a first exploration
of this program are presented and discussed.Comment: 27 pages, 5 figure
Pirate or subscriber? An exploratory study on italian consumers' music habits
Purpose of the paper: This paper analyzes Italian consumers’ music habits in
terms of online piracy behaviors and their interest toward subscription-based music
services (SBMS), i.e. services that for a small monthly fee give users legal access to vast
music libraries across multiple devices. The objective is to try and profile a piracy-prone
consumer and explore if SBMS could be a viable alternative to online music piracy in
Italy, where the general piracy rate is very high.
Methodology: The study is based on an empirical quantitative analysis through the
collection of 505 questionnaires completed by Italian consumers.
Findings: The paper highlights how Italian consumers reflect the ‘attitude-behavior
gap’ in music consumption, as they perceive online music piracy as ethically wrong, yet
they still show low preference for the legal, reasonably priced choice (such as SBMS).
Younger, male, lower education, students have the highest propensity towards online
piracy. In addition, consumers’ awareness, familiarity and interest in subscriptionbased
music services are still very low.
Research limitations: The limitations of the paper are linked mainly to the adapted
scales, to the omission of alternative determinants of attitude towards piracy, to the
composition of the sample and for analyzing only two subscription-based music services
(Napster and Spotify).
Managerial implications: The results call for greater efforts by music industry
actors and public institutions to educate Italian consumers about the consequences of
their online piracy behavior and the possible solutions offered by SBMS.
Originality of the paper: This paper is the first to focus on Italian consumers’
music habits, their attitude and behavior towards online piracy and their interest
toward subscription-based music services as a viable alternative
Nuclear response for the Skyrme effective interaction with zero-range tensor terms. II. Sum rules and instabilities
The formalism of linear response theory for Skyrme forces including tensor
terms presented in article [1] is generalized for the case of a Skyrme energy
density functional in infinite matter. We also present analytical results for
the odd-power sum rules, with particular attention to the inverse energy
weighted sum rule, , as a tool to detect instabilities in Skyrme
functionals.Comment: Submitted to Phys. Rev.
Recognizing myofascial pelvic pain in the female patient with chronic pelvic pain.
Myofascial pelvic pain (MFPP) is a major component of chronic pelvic pain (CPP) and often is not properly identified by health care providers. The hallmark diagnostic indicator of MFPP is myofascial trigger points in the pelvic floor musculature that refer pain to adjacent sites. Effective treatments are available to reduce MFPP, including myofascial trigger point release, biofeedback, and electrical stimulation. An interdisciplinary team is essential for identifying and successfully treating MFPP
Extended Skyrme Equation of State in asymmetric nuclear matter
We present a new equation of state for infinite systems (symmetric,
asymmetric and neutron matter) based on an extended Skyrme functional
constrained by microscopic Brueckner-Bethe-Goldstone results. The resulting
equation of state reproduces with very good accuracy the main features of
microscopic calculations and it is compatible with recent measurements of two
times Solar-mass neutron stars. We provide all necessary analytical expressions
to facilitate a quick numerical implementation of quantities of astrophysical
interest
Linear response in infinite nuclear matter as a tool to reveal finite size instabilities
Nuclear effective interactions are often modelled by simple analytical
expressions such as the Skyrme zero-range force. This effective interaction
depends on a limited number of parameters that are usually fitted using
experimental data obtained from doubly magic nuclei. It was recently shown that
many Skyrme functionals lead to the appearance of instabilities, in particular
when symmetries are broken, for example unphysical polarization of odd-even or
rotating nuclei. In this article, we show how the formalism of the linear
response in infinite nuclear matter can be used to predict and avoid the
regions of parameters that are responsible for these unphysical instabilities.Comment: Based on talk presented at 18th Nuclear Physics Workshop "Maria and
Pierre Curie", 2011, Kazimierz, Polan
Spurious finite-size instabilities in nuclear energy density functionals: spin channel
It has been recently shown, that some Skyrme functionals can lead to
non-converging results in the calculation of some properties of atomic nuclei.
A previous study has pointed out a possible link between these convergence
problems and the appearance of finite-size instabilities in symmetric nuclear
matter (SNM) around saturation density.
We show that the finite-size instabilities not only affect the ground state
properties of atomic nuclei, but they can also influence the calculations of
vibrational excited states in finite nuclei. We perform systematic fully-self
consistent Random Phase Approximation (RPA) calculations in spherical
doubly-magic nuclei. We employ several Skyrme functionals and vary the
isoscalar and isovector coupling constants of the time-odd term
. We determine critical values of these
coupling constants beyond which the RPA calculations do not converge because
RPA the stability matrix becomes non-positive.By comparing the RPA calculations
of atomic nuclei with those performed for SNM we establish a correspondence
between the critical densities in the infinite system and the critical coupling
constants for which the RPA calculations do not converge. We find a
quantitative stability criterion to detect finite-size instabilities related to
the spin term of a functional. This
criterion could be easily implemented into the standard fitting protocols to
fix the coupling constants of the Skyrme functional
Fitting Skyrme functionals using linear response theory
Recently, it has been recently shown that the linear response theory in
symmetric nuclear matter can be used as a tool to detect finite size
instabilities for different Skyrme functionals. In particular it has been shown
that there is a correlation between the density at which instabilities occur in
infinite matter and the instabilities in finite nuclei. In this article we
present a new fitting protocol that uses this correlation to add new additional
constraint in Symmetric Infinite Nuclear Matter in order to ensure the
stability of finite nuclei against matter fluctuation in all spin and isospin
channels. As an application, we give the parameters set for a new Skyrme
functional which includes central and spin-orbit parts and which is free from
instabilities by construction.Comment: Proceeding of 19th Nuclear Physics Workshop "Marie & Pierre Curie"
Kazimierz 201
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