scholarly journals NUCLEAR MATTER AND NEUTRON STARS IN A QUARK-HADRON MODEL

2011 ◽  
Vol 20 (supp02) ◽  
pp. 125-132
Author(s):  
STEFAN SCHRAMM ◽  
RODRIGO P. NEGREIROS ◽  
T. SCHÜRHOFF ◽  
VERONICA DEXHEIMER
Keyword(s):  
Phase Transitions ◽  
Neutron Stars ◽  
Nuclear Matter ◽  
High Temperatures ◽  
Low Temperatures ◽  
Degrees Of Freedom ◽  
Equations Of State ◽  
First Order ◽  
First Order Phase ◽  
Hadron Model

One of the difficulties in describing chiral symmetry and deconfinement phase transitions in strongly interacting matter at high temperatures as well as at high densities stems from the fact that one has to deal with very different degrees of freedom on both sides of the phase transition. Hadrons exist at low temperatures/densities whereas quarks and gluons occur in the other extreme. Gluing two separate equations of state together will necessarily lead to first-order phase transitions (which are not expected, at least not at small densities and high temperatures). In order to remedy this problem a unified model of quarks and hadrons (the QH model) has been developed that integrates both degrees of freedom in an effective chiral flavor-SU(3) ansatz. Results for nuclear matter and neutron stars for the purely hadronic part of the theory and then results for excited matter and stars for the full QH model are presented. Various extensions of this approach are discussed.

scholarly journals Phase transitions in neutron stars

2018 ◽  
Vol 27 (11) ◽  
pp. 1830008 ◽  
Author(s):  
V. Dexheimer ◽  
L. T. T. Soethe ◽  
J. Roark ◽  
R. O. Gomes ◽  
S. O. Kepler ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Equation Of State ◽  
Neutron Stars ◽  
Order Phase Transition ◽  
Dense Matter ◽  
First Order ◽  
The Core ◽  
First Order Phase Transition ◽  
First Order Phase

In this paper, we review the most common descriptions for the first-order phase transition to deconfined quark matter in the core of neutron stars. We also present a new description of these phase transitions in the core of proto-neutron stars, in which more constraints are enforced so as to include trapped neutrinos. Finally, we calculate the emission of gravitational waves associated with deconfinement phase transitions, discuss the possibility of their detection, and how this would provide information about the equation of state of dense matter.

scholarly journals Diffusionless first-order phase transitions in systems with frozen configurational degrees of freedom

1991 ◽  
Vol 44 (13) ◽  
pp. 6715-6722 ◽  
Author(s):  
Antoni Planes ◽  
Eduard Vives ◽  
Teresa Castán
Keyword(s):  
Phase Transitions ◽  
Degrees Of Freedom ◽  
First Order ◽  
First Order Phase

scholarly journals Electric properties of olive oil under pressure

2021 ◽  
Author(s):  
L. T. Pawlicki ◽  
R. M. Siegoczyński ◽  
S. Ptasznik ◽  
K. Marszałek
Keyword(s):  
Molecular Structure ◽  
Phase Transition ◽  
Phase Diagram ◽  
Phase Transitions ◽  
Olive Oil ◽  
Material Parameters ◽  
First Order ◽  
Long Time ◽  
Capacitive Reactance ◽  
First Order Phase

AbstractThe main purpose of the experiment was a thermodynamic research with use of the electric methods chosen. The substance examined was olive oil. The paper presents the resistance, capacitive reactance, relative permittivity and resistivity of olive. Compression was applied with two mean velocities up to 450 MPa. The results were shown as functions of pressure and time and depicted on the impedance phase diagram. The three first order phase transitions have been detected. All the changes in material parameters were observed during phase transitions. The material parameters measured turned out to be the much more sensitive long-time phase transition factors than temperature. The values of material parameters and their dependence on pressure and time were compared with the molecular structure, arrangement of molecules and interactions between them. Knowledge about olive oil parameters change with pressure and its phase transitions is very important for olive oil production and conservation.

scholarly journals Fate of false vacua in holographic first-order phase transitions

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Francesco Bigazzi ◽  
Alessio Caddeo ◽  
Aldo L. Cotrone ◽  
Angel Paredes
Keyword(s):  
Phase Transitions ◽  
Chiral Symmetry ◽  
Metastable Phase ◽  
Chiral Symmetry Breaking ◽  
Model Parameters ◽  
Temperature Phase ◽  
Thin Wall ◽  
Critical Temperatures ◽  
First Order ◽  
First Order Phase

Abstract Using the holographic correspondence as a tool, we study the dynamics of first-order phase transitions in strongly coupled gauge theories at finite temperature. Considering an evolution from the large to the small temperature phase, we compute the nucleation rate of bubbles of true vacuum in the metastable phase. For this purpose, we find the relevant configurations (bounces) interpolating between the vacua and we compute the related effective actions. We start by revisiting the compact Randall-Sundrum model at high temperature. Using holographic renormalization, we compute the derivative term in the effective bounce action, that was missing in the literature. Then, we address the full problem within the top-down Witten-Sakai-Sugimoto model. It displays both a confinement/deconfinement and a chiral symmetry breaking/restoration phase transition which, depending on the model parameters, can happen at different critical temperatures. For the confinement/deconfinement case we perform the numerical analysis of an effective description of the transition and also provide analytic expressions using thick and thin wall approximations. For the chiral symmetry transition, we implement a variational approach that allows us to address the challenging non-linear problem stemming from the Dirac-Born-Infeld action.

scholarly journals Charge density waves and their transitions in anisotropic quantum Hall systems

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yuchi He ◽  
Kang Yang ◽  
Mark Oliver Goerbig ◽  
Roger S. K. Mong
Keyword(s):  
Phase Transitions ◽  
Charge Density ◽  
Density Wave ◽  
Quantum Hall ◽  
Charge Density Waves ◽  
Stripe Phase ◽  
Electron Bubble ◽  
First Order ◽  
Bubble Phase ◽  
First Order Phase

AbstractIn recent experiments, external anisotropy has been a useful tool to tune different phases and study their competitions. In this paper, we look at the quantum Hall charge density wave states in the N = 2 Landau level. Without anisotropy, there are two first-order phase transitions between the Wigner crystal, the 2-electron bubble phase, and the stripe phase. By adding mass anisotropy, our analytical and numerical studies show that the 2-electron bubble phase disappears and the stripe phase significantly enlarges its domain in the phase diagram. Meanwhile, a regime of stripe crystals that may be observed experimentally is unveiled after the bubble phase gets out. Upon increase of the anisotropy, the energy of the phases at the transitions becomes progressively smooth as a function of the filling. We conclude that all first-order phase transitions are replaced by continuous phase transitions, providing a possible realisation of continuous quantum crystalline phase transitions.

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