scholarly journals From neutron and quark stars to black holes

2020 ◽  
Author(s):  
Wanpeng Tan
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quark Matter ◽  
Mean Field ◽  
New Physics ◽  
Quantum Theories ◽  
Spacetime Geometry ◽  
Quark Stars ◽  
Quantum Particles ◽  
Black Hole Interior

New physics and models for the most compact astronomical objects - neutron / quark stars and black holes are proposed. Under the new supersymmetric mirror models, neutron stars at least heavy ones could be born from hot deconfined quark matter in the core with a mass limit less than $2.5 M_\odot$. Even heavier cores will inevitably collapse into black holes as quark matter with more deconfined quark flavors becomes ever softer during the staged restoration of flavor symmetry. With new understanding of gravity as mean field theories emergent from the underlying quantum theories for providing the smooth background spacetime geometry for quantum particles, the black hole interior can be described well as a perfect fluid of free massless Majorana fermions and gauge bosons under the new genuine 2-d model. In particular, the conformal invariance on a 2-d torus for the black hole gives rise to desired consistent results for the interior microphysics and structures including its temperature, density, and entropy. Conjectures for further studies of the black hole and the early universe are also discussed in the new framework.

The entropy evolution of a noncommutative black hole under Hawking radiation

2020 ◽  
Vol 35 (30) ◽  
pp. 2050194
Author(s):  
Peng Wen ◽  
Xin-Yang Wang ◽  
Wen-Biao Liu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Hawking Radiation ◽  
New Physics ◽  
Evaporation Process ◽  
Final State ◽  
Loss Of Information ◽  
Proportion Function ◽  
Interior Volume

By calculating the entropy of a scalar field in the interior volume of noncommutative black holes and considering an infinitesimal process of Hawking radiation, a proportion function is constructed that reflects the evolution relation between the scalar field entropy and Bekenstein–Hawking entropy under Hawking radiation. Comparing with the case of Schwarzschild black holes, the new physics of this research can be expanded to the later stage of Hawking radiation. From the result, we find that the proportion function is still a constant in the earlier stage of Hawking radiation, which is identical to the case of Schwarzschild black holes. As Hawking radiation goes into the later stage, the behavior of the function will be dominated by the noncommutative effect. In this circumstance, the proportion function is no longer a constant and decreases with the evaporation process. When the noncommutative black hole evolves into its final state with Hawking radiation, the interior volume will converge to a certain value, which implies that the loss of information of the black hole during the evaporation process will finally be stored in the limited interior volume.

scholarly journals External energy paradigm for black holes

2018 ◽  
Vol 33 (31) ◽  
pp. 1844025 ◽  
Author(s):  
Yuan K. Ha
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Energy ◽  
Electrostatic Energy ◽  
New Paradigm ◽  
External Energy ◽  
Quantum Particles ◽  
Remarkable Result ◽  
The Moment ◽  
Constituent Mass

A new paradigm for black holes is introduced. It is known as the External Energy Paradigm. The paradigm asserts that all energies of a black hole are external quantities; they are absent inside the horizon. These energies include constituent mass, gravitational energy, electrostatic energy, rotational energy, heat energy, etc. As a result, quantum particles with charges and spins cannot exist inside the black hole. To validate the conclusion, we derive the moment of inertia of a Schwarzschild black hole and find that it is exactly equal to mass [Formula: see text] (Schwarzschild radius)2, indicating that all mass of the black hole is located at the horizon. This remarkable result can resolve several long-standing paradoxes in black hole theory; such as why entropy is proportional to area and not to volume, the singularity problem, the information loss problem and the perplexing firewall controversy.

scholarly journals SUPERSYMMETRY VERSUS BLACK HOLES AT THE LHC

2008 ◽  
Vol 23 (35) ◽  
pp. 2987-2996 ◽  
Author(s):  
ARUNAVA ROY ◽  
MARCO CAVAGLIÀ
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Spectrum ◽  
Large Hadron Collider ◽  
Extra Dimensions ◽  
Hadron Collider ◽  
New Physics ◽  
Event Shape ◽  
High Transverse Momentum ◽  
Dilepton Invariant Mass

Supersymmetry and extra dimensions are the two most promising candidates for new physics at the TeV scale. Supersymmetric particles or extra-dimensional effects could soon be observed at the Large Hadron Collider. We propose a simple but effective method to discriminate the two models: the analysis of isolated leptons with high transverse momentum. Black hole events are simulated with the CATFISH black hole generator. Supersymmetry simulations use a combination of PYTHIA and ISAJET, the latter providing the mass spectrum. Our results show that the measure of the dilepton invariant mass provides a promising signature to differentiate supersymmetry and black hole events at the Large Hadron Collider. Analysis of event-shape variables and multilepton events complement and strengthen this conclusion.

On the stability of two-flavor and three-flavor quark matter in quark stars within the framework of NJL model

2020 ◽  
Vol 35 (39) ◽  
pp. 2050321 ◽  
Author(s):  
Qianyi Wang ◽  
Tong Zhao ◽  
Hongshi Zong
Keyword(s):  
Quark Matter ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Chiral Phase ◽  
Quark Stars ◽  
Njl Model ◽  
The Stability ◽  
Chiral Susceptibility ◽  
Strong Interaction Matter

Following our recently proposed self-consistent mean field approximation approach, we have done some researches on the chiral phase transition of strong interaction matter within the framework of Nambu-Jona-Lasinio (NJL) model. The chiral susceptibility and equation of state (EOS) are computed in this work for both two-flavor and three-flavor quark matter for contrast. The Pauli–Villars scheme, which can preserve gauge invariance, is used in this paper. Moreover, whether the three-flavor quark matter is more stable than the two-flavor quark matter or not in quark stars is discussed in this work. In our model, when the bag constant are the same, the two-flavor quark matter has a higher pressure than the three-flavor quark matter, which is different from what Witten proposed in his pioneering work.

Dark Energy

2021 ◽  
pp. 79-88
Author(s):  
Gianfranco Bertone
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Energy ◽  
Gravitational Waves ◽  
Quantum Physics ◽  
New Physics ◽  
The Universe

I discuss here black holes, extreme astronomical objects that swallow all forms of matter and radiation surrounding them, and leave behind, as physicist John A. Wheeler said, only their ‘gravitational aura’. These endlessly fascinating objects are the gates where gravity meets quantum physics. Since the pioneering work of scientists like S. Hawking, black holes have become ‘theoretical laboratories’ to explore new physics theories. I discuss how the discovery of gravitational waves from black holes, and the first image of a black hole revealed in 2019, have transformed the study of black holes, and may soon lead to new ground-breaking discoveries. The Universe will disappear. Slowly, it will grow dimmer and dimmer, until it disappears completely.

scholarly journals Primordial black holes and the origin of the matter–antimatter asymmetry

2019 ◽  
Vol 377 (2161) ◽  
pp. 20190091 ◽  
Author(s):  
Juan García-Bellido
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Cold Dark Matter ◽  
Hot Spot ◽  
Large Mass ◽  
New Physics ◽  
Primordial Black Holes ◽  
Far From Equilibrium ◽  
The Universe

We review here a new scenario of hot spot electroweak baryogenesis where the local energy released in the gravitational collapse to form primordial black holes (PBHs) at the quark-hadron (QCD) epoch drives over-the-barrier sphaleron transitions in a far from equilibrium environment with just the standard model CP violation. Baryons are efficiently produced in relativistic collisions around the black holes and soon redistribute to the rest of the universe, generating the observed matter–antimatter asymmetry well before primordial nucleosynthesis. Therefore, in this scenario there is a common origin of both the dark matter to baryon ratio and the photon to baryon ratio. Moreover, the sudden drop in radiation pressure of relativistic matter at H 0 / W ± / Z 0 decoupling, the QCD transition and e + e − annihilation enhances the probability of PBH formation, inducing a multi-modal broad mass distribution with characteristic peaks at 10 −6 , 1, 30 and 10 6   M ⊙ , rapidly falling at smaller and larger masses, which may explain the LIGO–Virgo black hole mergers as well as the OGLE-GAIA microlensing events, while constituting all of the cold dark matter today. We predict the future detection of binary black hole (BBH) mergers in LIGO with masses between 1 and 5  M ⊙ , as well as above 80  M ⊙ , with very large mass ratios. Next generation gravitational wave and microlensing experiments will be able to test this scenario thoroughly. This article is part of a discussion meeting issue ‘Topological avatars of new physics’.

scholarly journals BLACK HOLES RADIATE BUT DO NOT EVAPORATE

2005 ◽  
Vol 14 (12) ◽  
pp. 2257-2261 ◽  
Author(s):  
HRVOJE NIKOLIĆ
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Negative Energy ◽  
Black Hole Mass ◽  
Black Hole Radiation ◽  
Semiclassical Gravity ◽  
Black Hole Interior ◽  
Semiclassical State ◽  
Infinite Temperature

During the black hole radiation, the interior contains all the matter of the initial black hole, together with the negative energy quanta entangled with the exterior Hawking radiation. Neither the initial matter nor the negative energy quanta evaporate from the black hole interior. Therefore, the information is not lost during the radiation. The black hole mass eventually drops to zero in semiclassical gravity, but this semiclassical state has an infinite temperature and still contains all the initial matter together with the negative energy entangled with the exterior radiation.

scholarly journals Truly two-dimensional black holes under dimensional transitions of spacetime

2021 ◽  
Author(s):  
Wanpeng Tan
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Massive Star ◽  
Majorana Fermions ◽  
Two Dimensional ◽  
Gauge Bosons ◽  
The Core ◽  
Black Hole Interior

A sufficiently massive star in the end of its life will inevitably collapse into a black hole as more deconfined degrees of freedom make the core ever softer. One possible way to avoid the singularity in the end is by dimensional phase transition of spacetime. Indeed, the black hole interior, two-dimensional in nature, can be described well as a perfect fluid of free massless Majorana fermions and gauge bosons under a 2-d supersymmetric mirror model with new understanding of emergent gravity from dimensional evolution of spacetime. In particular, the 2-d conformal invariance of the black hole gives rise to desired consistent results for the interior microphysics and structures including its temperature, density, and entropy.

scholarly journals Finding pythons in unexpected places

2021 ◽  
Author(s):  
Netta Engelhardt ◽  
Geoff Penington ◽  
Arvin Shahbazi-Moghaddam
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mixed State ◽  
Crucial Role ◽  
State Dependence ◽  
Extremal Surface ◽  
Black Hole Interior ◽  
Exponential Complexity

Abstract We argue that novel (highly nonclassical) quantum extremal surfaces play a crucial role in reconstructing the black hole interior even for isolated, single-sided, non-evaporating black holes (i.e. with no auxiliary reservoir). Specifically, any code subspace where interior outgoing modes can be excited will have a quantum extremal surface in its maximally mixed state. We argue that as a result, reconstruction of interior outgoing modes is always exponentially complex. Our construction provides evidence in favor of a strong Python’s lunch proposal: that nonminimal quantum extremal surfaces are the exclusive source of exponential complexity in the holographic dictionary. We also comment on the relevance of these quantum extremal surfaces to the geometrization of state dependence in the typicality arguments for firewalls.

scholarly journals Properties of strange quark matter and strange quark stars

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Manisha Kumari ◽  
Arvind Kumar
Keyword(s):  
Quark Matter ◽  
Strange Quark ◽  
Present Model ◽  
Constituent Quark ◽  
Mean Field ◽  
Strange Quark Matter ◽  
Model Calculations ◽  
Quark Stars ◽  
Star Evolution ◽  
Constituent Quark Mass

AbstractA Polyakov chiral $$\text {SU(3)}$$ SU(3) quark mean-field (PCQMF) model is applied to study the properties of strange quark matter (SQM) and strange quark star (SQS) in $$\beta $$ β -equilibrium. The effect of increasing the strength of vector interactions on the effective constituent quark mass, particle fractions, and the thermodynamical properties such as pressure, energy density, and the speed of sound is investigated. We investigate the above properties for the SQM relevant for various stages of star evolution, i.e., considering with/without trapped neutrinos and zero/finite entropy. The finite lepton fraction and the entropy of the medium is observed to cause the stiffness in the equation of state (EoS). Finally, we calculate the mass-radius relation and the dimensionless tidal deformability within the present model calculations and compare the results to the recent studies.

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