scholarly journals Neutron Star Mergers: Probing the EoS of Hot, Dense Matter by Gravitational Waves

Particles ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 44-56 ◽  
Author(s):  
Matthias Hanauske ◽  
Jan Steinheimer ◽  
Anton Motornenko ◽  
Volodymyr Vovchenko ◽  
Luke Bovard ◽  
...  
Keyword(s):  
Phase Transition ◽  
Neutron Star ◽  
Gravitational Waves ◽  
Phase Structure ◽  
Heavy Ions ◽  
Compact Star ◽  
Dense Matter ◽  
Gluon Plasma ◽  
High Energy ◽  
Quark Phase

Gravitational waves, electromagnetic radiation, and the emission of high energy particles probe the phase structure of the equation of state of dense matter produced at the crossroad of the closely related relativistic collisions of heavy ions and of binary neutron stars mergers. 3 + 1 dimensional special- and general relativistic hydrodynamic simulation studies reveal a unique window of opportunity to observe phase transitions in compressed baryon matter by laboratory based experiments and by astrophysical multimessenger observations. The astrophysical consequences of a hadron-quark phase transition in the interior of a compact star will be focused within this article. Especially with a future detection of the post-merger gravitational wave emission emanated from a binary neutron star merger event, it would be possible to explore the phase structure of quantum chromodynamics. The astrophysical observables of a hadron-quark phase transition in a single compact star system and binary hybrid star merger scenario will be summarized within this article. The FAIR facility at GSI Helmholtzzentrum allows one to study the universe in the laboratory, and several astrophysical signatures of the quark-gluon plasma have been found in relativistic collisions of heavy ions and will be explored in future experiments.

scholarly journals Gravitational waves from binary compact star mergers in the context of strange matter

2018 ◽  
Vol 171 ◽  
pp. 20004 ◽  
Author(s):  
Matthias Hanauske ◽  
Zekiye Simay Yilmaz ◽  
Christina Mitropoulos ◽  
Luciano Rezzolla ◽  
Horst Stöcker
Keyword(s):  
Phase Transition ◽  
Neutron Star ◽  
Gravitational Waves ◽  
Spectral Properties ◽  
Compact Star ◽  
Interior Region ◽  
Strange Matter ◽  
Quark Phase

In this article we will focus on the appearance of the hadron-quark phase transition and the formation of strange matter in the interior region of the hypermassive neutron star and its conjunction with the spectral properties of the emitted gravitational waves (GWs). A strong hadron-quark phase transition might give rise to a mass-radius relation with a twin star shape and we will show in this article that a twin star collapse followed by a twin star oscillation is feasible. If such a twin star collapse would happen during the postmerger phase it will be imprinted in the GW-signal.

scholarly journals Multimessenger approaches to exploring dense matter in neutron stars

2021 ◽  
Author(s):  
◽  
Lukas Weih
Keyword(s):  
Phase Transition ◽  
Neutron Star ◽  
Nuclear Physics ◽  
Computational Cost ◽  
Dense Matter ◽  
High Energy ◽  
Radiative Transport ◽  
Binary Neutron Star ◽  
Starting Point ◽  
Numerical Astrophysics

High-energy astrophysics plays an increasingly important role in the understanding of our universe. On one hand, this is due to ground-breaking observations, like the gravitational-wave detections of the LIGO and Virgo network or the black-hole shadow observations of the EHT collaboration. On the other hand, the field of numerical relativity has reached a level of sophistication that allows for realistic simulations that include all four fundamental forces of nature. A prime example of how observations and theory complement each other can be seen in the studies following GW170817, the first detection of gravitational waves from a binary neutron-star merger. The same detection is also the chronological starting point of this Thesis. The plethora of information and constraints on nuclear physics derived from GW170817 in conjunction with theoretical computations will be presented in the first part of this Thesis. The second part goes beyond this detection and prepares for future observations when also the high-frequency postmerger signal will become detectable. Specifically, signatures of a quark-hadron phase transition are discussed and the specific case of a delayed phase transition is analyzed in detail. Finally, the third part of this Thesis focuses on the inclusion of radiative transport in numerical astrophysics. In the context of binary neutron-star mergers, radiation in the form of neutrinos is crucial for realistic long-term simulations. Two methods are introduced for treating radiation: the approximate state-of-the-art two-moment method (M1) and the recently developed radiative Lattice-Boltzmann method. The latter promises to be more accurate than M1 at a comparable computational cost. Given that most methods for radiative transport or either inaccurate or unfeasible, the derivation of this new method represents a novel and possibly paradigm-changing contribution to an accurate inclusion of radiation in numerical astrophysics.

scholarly journals Detecting the Hadron-Quark Phase Transition with Gravitational Waves

Universe ◽  
2019 ◽  
Vol 5 (6) ◽  
pp. 156 ◽  
Author(s):  
Matthias Hanauske ◽  
Luke Bovard ◽  
Elias Most ◽  
Jens Papenfort ◽  
Jan Steinheimer ◽  
...  
Keyword(s):  
Phase Transition ◽  
Neutron Star ◽  
Equation Of State ◽  
Gravitational Wave ◽  
Compact Star ◽  
Binary Neutron Star ◽  
Interesting Part ◽  
Merger Event ◽  
Tidal Deformations ◽  
Quark Phase

The long-awaited detection of a gravitational wave from the merger of a binary neutron star in August 2017 (GW170817) marks the beginning of the new field of multi-messenger gravitational wave astronomy. By exploiting the extracted tidal deformations of the two neutron stars from the late inspiral phase of GW170817, it is now possible to constrain several global properties of the equation of state of neutron star matter. However, the most interesting part of the high density and temperature regime of the equation of state is solely imprinted in the post-merger gravitational wave emission from the remnant hypermassive/supramassive neutron star. This regime was not observed in GW170817, but will possibly be detected in forthcoming events within the current observing run of the LIGO/VIRGO collaboration. Numerous numerical-relativity simulations of merging neutron star binaries have been performed during the last decades, and the emitted gravitational wave profiles and the interior structure of the generated remnants have been analysed in detail. The consequences of a potential appearance of a hadron-quark phase transition in the interior region of the produced hypermassive neutron star and the evolution of its underlying matter in the phase diagram of quantum cromo dynamics will be in the focus of this article. It will be shown that the different density/temperature regions of the equation of state can be severely constrained by a measurement of the spectral properties of the emitted post-merger gravitational wave signal from a future binary compact star merger event.

scholarly journals Balance Function in High-Energy Collisions

2015 ◽  
Vol 2015 ◽  
pp. 1-24 ◽  
Author(s):  
A. Tawfik ◽  
Asmaa G. Shalaby
Keyword(s):  
Phase Transition ◽  
Beam Energy ◽  
High Energy Physics ◽  
System Size ◽  
Gluon Plasma ◽  
High Energy ◽  
Essential Properties ◽  
Balance Functions ◽  
Quark Phase ◽  
Energy Physics

Aspects and implications of the balance functions (BF) in high-energy physics are reviewed. The various calculations and measurements depending on different quantities, for example, system size, collisions centrality, and beam energy, are discussed. First, the different definitions including advantages and even short-comings are highlighted. It is found that BF, which are mainly presented in terms of relative rapidity, and relative azimuthal and invariant relative momentum, are sensitive to the interaction centrality but not to the beam energy and can be used in estimating the hadronization time and the hadron-quark phase transition. Furthermore, the quark chemistry can be determined. The chemical evolution of the new-state-of-matter, the quark-gluon plasma, and its temporal-spatial evolution, femtoscopy of two-particle correlations, are accessible. The production time of positive-negative pair of charges can be determined from the widths of BF. Due to the reduction in the diffusion time, narrowed widths refer to delayed hadronization. It is concluded that BF are powerful tools characterizing hadron-quark phase transition and estimating some essential properties.

scholarly journals QCD PHASE TRANSITION IN DGP BRANE COSMOLOGY

2012 ◽  
Vol 21 (08) ◽  
pp. 1250069 ◽  
Author(s):  
K. ATAZADEH ◽  
A. M. GHEZELBASH ◽  
H. R. SEPANGI
Keyword(s):  
Phase Transition ◽  
Energy Density ◽  
Early Universe ◽  
Effective Temperature ◽  
Quark Gluon Plasma ◽  
Friedmann Equation ◽  
Gluon Plasma ◽  
High Energy ◽  
Brane World ◽  
High Energy Density

In the standard picture of cosmology it is predicted that a phase transition, associated with chiral symmetry breaking after the electroweak transition, has occurred at approximately 10μ seconds after the Big Bang to convert a plasma of free quarks and gluons into hadrons. We consider the quark-hadron phase transition in a Dvali, Gabadadze and Porrati (DGP) brane world scenario within an effective model of QCD. We study the evolution of the physical quantities useful for the study of the early universe, namely, the energy density, temperature and the scale factor before, during and after the phase transition. Also, due to the high energy density in the early universe, we consider the quadratic energy density term that appears in the Friedmann equation. In DGP brane models such a term corresponds to the negative branch (ϵ = -1) of the Friedmann equation when the Hubble radius is much smaller than the crossover length in 4D and 5D regimes. We show that for different values of the cosmological constant on a brane, λ, phase transition occurs and results in decreasing the effective temperature of the quark-gluon plasma and of the hadronic fluid. We then consider the quark-hadron transition in the smooth crossover regime at high and low temperatures and show that such a transition occurs along with decreasing the effective temperature of the quark-gluon plasma during the process of the phase transition.

scholarly journals A Description of Pseudorapidity Distributions of Charged Particles Produced in Au+Au Collisions at RHIC Energies

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Z. J. Jiang ◽  
Dongfang Xu ◽  
Yan Huang
Keyword(s):  
Phase Transition ◽  
Heavy Ion Collisions ◽  
Charged Particles ◽  
Dense Matter ◽  
Heavy Ion ◽  
High Energy ◽  
Low Energy ◽  
Ion Collisions ◽  
Rapidity Distributions ◽  
Pseudorapidity Distributions

In heavy ion collisions, charged particles come from two parts: the hot and dense matter and the leading particles. In this paper, the hot and dense matter is assumed to expand according to the hydrodynamic model including phase transition and decouples into particles via the prescription of Cooper-Frye. The leading particles are as usual supposed to have Gaussian rapidity distributions with the number equaling that of participants. The investigations of this paper show that, unlike low energy situations, the leading particles are essential in describing the pseudorapidity distributions of charged particles produced in high energy heavy ion collisions. This might be due to the different transparencies of nuclei at different energies.

scholarly journals Stellar Collapse with Hadron-Quark Phase Transition of Hot and Dense Matter

2008 ◽  
Vol 174 ◽  
pp. 76-79
Author(s):  
Ken'ichiro Nakazato ◽  
Kohsuke Sumiyoshi ◽  
Shoichi Yamada
Keyword(s):  
Phase Transition ◽  
Dense Matter ◽  
Stellar Collapse ◽  
Quark Phase
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