183 research outputs found
Finite size effect on the thermodynamics of a hot and magnetized hadron resonance gas
The thermodynamic properties of a non-interacting ideal Hadron Resonance Gas
(HRG) of finite volume have been studied in the presence of an external
magnetic field. The inclusion of background magnetic field in the calculation
of thermodynamic potential is done by the modification of the dispersion
relations of the charged hadrons in terms of Landau quantization. The
generalized Matsubara prescription has been employed to take into account the
finite size effects in which a periodic (anti-periodic) boundary conditions is
considered for the mesons (baryons). We find significant effects of the
magnetic field as well as system size on the temperature dependence of energy
density, longitudinal and transverse pressure especially in low temperature
regions. The HRG is found to exhibit diamagnetism (paramagnetism) in the low
(high) temperature region whereas the finite size effect is seen to strengthen
the diamagnetic behavior of the medium.Comment: Version Published in Modern Physics Letters
A Novel Loss Function Utilizing Wasserstein Distance to Reduce Subject-Dependent Noise for Generalizable Models in Affective Computing
Emotions are an essential part of human behavior that can impact thinking,
decision-making, and communication skills. Thus, the ability to accurately
monitor and identify emotions can be useful in many human-centered applications
such as behavioral training, tracking emotional well-being, and development of
human-computer interfaces. The correlation between patterns in physiological
data and affective states has allowed for the utilization of deep learning
techniques which can accurately detect the affective states of a person.
However, the generalisability of existing models is often limited by the
subject-dependent noise in the physiological data due to variations in a
subject's reactions to stimuli. Hence, we propose a novel cost function that
employs Optimal Transport Theory, specifically Wasserstein Distance, to scale
the importance of subject-dependent data such that higher importance is
assigned to patterns in data that are common across all participants while
decreasing the importance of patterns that result from subject-dependent noise.
The performance of the proposed cost function is demonstrated through an
autoencoder with a multi-class classifier attached to the latent space and
trained simultaneously to detect different affective states. An autoencoder
with a state-of-the-art loss function i.e., Mean Squared Error, is used as a
baseline for comparison with our model across four different commonly used
datasets. Centroid and minimum distance between different classes are used as a
metrics to indicate the separation between different classes in the latent
space. An average increase of 14.75% and 17.75% (from benchmark to proposed
loss function) was found for minimum and centroid euclidean distance
respectively over all datasets.Comment: 9 page
Effects of quark anomalous magnetic moment on the thermodynamical properties and mesonic excitations of magnetized hot and dense matter in PNJL model
Various thermodynamic quantities and the phase diagram of strongly
interacting hot and dense magnetized quark matter are obtained with the -flavour Nambu-Jona-Lasinio model with Polyakov loop considering finite values
of the anomalous magnetic moment (AMM) of the quarks. Susceptibilities
associated with constituent quark mass and traced Polyakov loop are used to
evaluate chiral and deconfinement transition temperatures. It is found that,
inclusion of the AMM of the quarks in presence of the background magnetic field
results in a substantial decrease in the chiral as well as deconfinement
transition temperatures in contrast to an enhancement in the chiral transition
temperature in its absence. Using standard techniques of finite temperature
field theory, the two point thermo-magnetic mesonic correlation functions in
the scalar () and neutral pseudoscalar () channels are evaluated
to calculate the masses of and considering the AMM of the
quarks.Comment: Version published in European Physical Journal
Dilepton production from hot and magnetized hadronic matter
The rate of dilepton emission from a magnetized hot hadronic medium is
calculated in the framework of real time formalism of finite temperature field
theory. We evaluate the one loop self-energy of neutral rho-meson containing
thermo-magnetic propagators for the charged pions in the loop. The in-medium
thermo-magnetic spectral function of rho obtained by solving the
Dyson-Schwinger equation is shown to be proportional to the dilepton production
rate. The study of the analytic structure of the neutral rho-meson spectral
function in such a medium shows that in addition to the usual contribution
coming from the Unitary cut beyond the two-pion threshold there is a
non-trivial yield in the low invariant mass region originating due to the fact
that the charged pions occupy different Landau levels before and after
scattering with the neutral rho-meson and is purely a finite magnetic field
effect.Comment: Version Accepted for publication in Physical Review
Insignificance of the anomalous magnetic moment of the quarks in presence of chiral imbalance
We incorporate the anomalous magnetic moment (AMM) of quarks in the framework
of PNJL model to study hot and dense magnetised matter with chiral imbalance.
For this purpose, the eigen energy solution of the Dirac equation is obtained
in presence of constant background magnetic field and chiral chemical potential
(CCP) along with the minimal anomalous magnetic moment interaction of the
fermion. Although there is a marginal enhancement in the IMC behaviour of the
quark condensate due to the combined effects of AMM and CCP, we find that the
overall behaviour of the Polyakov loop and the chiral charge density is
dominated by the chiral chemical potential. It is further shown that the AMM
effects in presence of CCP remains insignificant even after consideration of
thermo-magnetically modified moments.Comment: Version published in European Physical Journal
Viscous coefficients and thermal conductivity of a gas mixture in the medium
The temperature and density dependence of the relaxation times, thermal
conductivity, shear viscosity and bulk viscosity for a hot and dense gas
consisting of pions, kaons and nucleons have been evaluated in the kinetic
theory approach. The in-medium cross-sections for , and
scatterings were obtained by using complete propagators for the exchanged
, , and excitations derived using thermal field
theoretic techniques. Notable deviations can be observed in the temperature
dependence of , and when compared with corresponding
calculations using vacuum cross-sections usually employed in the literature.
The value of the specific shear viscosity is found to be in agreement
with available estimates.Comment: Version published in European Physical Journal
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