scholarly journals Properties of Relativistic Linear Stellar Models

1982 ◽  
Vol 69 ◽  
pp. 73-78
Author(s):  
V. Ureche
Keyword(s):  
Black Holes ◽  
Gravitational Field ◽  
Neutron Stars ◽  
Stellar Evolution ◽  
Space Time ◽  
Relativistic Stars ◽  
Strong Gravitational Field ◽  
Stellar Models ◽  
Late Stages

In the late stages of stellar evolution, relativistic objects are formed, such as neutron stars or black holes. These relativistic stars possess a strong gravitational field, therefore their structure and their space-time geometry can be described only in the frame of GRT (Zeldovich and Novikov, 1971; Misner, Thorne and Wheeler, 1973). For this purpose, the following four-dimensional interval is used (spherical gravitational field), (Zeldovich and Novikov, 1971).

The stellar graveyard

2019 ◽  
pp. 177-206
Author(s):  
Nils Andersson
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Stellar Evolution ◽  
White Dwarfs ◽  
Supermassive Black Holes ◽  
Compact Objects ◽  
Fermi Gases ◽  
The 1950S

This chapter introduces the different classes of compact objects—white dwarfs, neutron stars, and black holes—that are relevant for gravitational-wave astronomy. The ideas are placed in the context of developing an understanding of the likely endpoint(s) of stellar evolution. Key ideas like Fermi gases and the Chandrasekhar mass are discussed, as is the emergence of general relativity as a cornerstone of astrophysics in the 1950s. Issues associated with different formation channels for, in particular, black holes are considered. The chapter ends with a discussion of the supermassive black holes that are found at the centre of galaxies.

3. Extrasolar tests of gravity

2017 ◽  
pp. 35-45
Author(s):  
Timothy Clifton
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Field ◽  
Solar System ◽  
Neutron Stars ◽  
Event Horizon ◽  
Gravitational Fields ◽  
Binary Pulsars ◽  
Tests Of Gravity ◽  
Triple Star

By studying objects outside our Solar System, we can observe star systems with far greater gravitational fields. ‘Extrasolar tests of gravity’ considers stars of different sizes that have undergone gravitational collapse, including white dwarfs, neutron stars, and black holes. A black hole consists of a region of space-time enclosed by a surface called an event horizon. The gravitational field of a black hole is so strong that anything that finds its way inside the event horizon can never escape. Other star systems considered are binary pulsars and triple star systems. With the invention of even more powerful telescopes, there will be more tantalizing possibilities for testing gravity in the future.

scholarly journals Entropic gravity from noncommutative black holes

2017 ◽  
Vol 15 (01) ◽  
pp. 1850004 ◽  
Author(s):  
Rafael C. Nunes ◽  
Hooman Moradpour ◽  
Edésio M. Barboza ◽  
Everton M. C. Abreu ◽  
Jorge Ananias Neto
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Field ◽  
Cosmological Constant ◽  
Black Hole Entropy ◽  
Space Time ◽  
Isotropic Universe ◽  
Entropic Gravity ◽  
The Universe

In this paper, we investigated the effects of a noncommutative (NC) space-time on the dynamics of the Universe. We generalize the black hole entropy for a NC black hole. Then, using the entropic gravity formalism, we will show that the noncommutativity changes the strength of the gravitational field. By applying this result to a homogeneous and isotropic Universe containing nonrelativistic matter and a cosmological constant, we show that the modified scenario by the noncommutativity of the space-time is a better fit to the obtained data than the standard one at 68% CL.

Realistic models of Globular Clusters with white dwarfs, neutron stars and black holes using GPU supercomputer

2019 ◽  
Vol 15 (S357) ◽  
pp. 206-210
Author(s):  
Bhusan Kayastha ◽  
Long Wang ◽  
Peter Berczik ◽  
Xiaoying Pang ◽  
Manuel Arca Sedda ◽  
...  
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Stellar Evolution ◽  
Globular Clusters ◽  
White Dwarfs ◽  
Cataclysmic Variables ◽  
Compact Objects ◽  
Black Hole Binaries ◽  
Formation And Evolution ◽  
Evolution With Time

AbstractWe present some results from the DRAGON simulations, a set of four direct N-body simulations of globular clusters (GCs) with a million stars and five percent initial (primordial) binaries. These simulations were undertaken with the NBODY6++GPU code, which allowed us to follow dynamical and stellar evolution of individual stars and binaries, formation and evolution of white dwarfs, neutron stars, and black holes, and the effect of a galactic tidal field. The simulations are the largest existing models of a realistic globular cluster over its full lifetime of 12 billion years. In particular we will show here an investigation of the population of binaries including compact objects (such as white dwarfs - cataclysmic variables and merging black hole binaries in the model as counterparts of LIGO/Virgo sources); their distribution in the cluster and evolution with time.

scholarly journals 10.6. Evaporating stars at galactic centers?

1998 ◽  
Vol 184 ◽  
pp. 441-442
Author(s):  
G. Meynet ◽  
N. Mowlavi ◽  
D. Schaerer ◽  
M. Pindao
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
White Dwarfs ◽  
Massive Stars ◽  
Stellar Winds ◽  
Complete Evaporation ◽  
Galactic Centers ◽  
Stellar Models

The Geneva group has computed a complete grid of stellar models from 0.8 to 60 M⊙ at a metallicity of Z=0.100 (i.e. 5 times solar, Mowlavi et al. 1997). These stellar models present interesting features such as the nearly complete evaporation of the most massive stars due to intense stellar winds. For instance, for Z >> 0.040, final stages of massive stars (M > 60 M⊙) might be white dwarfs rather than neutron stars or black holes.

THE BEHAVIOR OF THE EFFECTIVE COUPLING CONSTANTS FOR E6 GUT IN CURVED SPACE-TIME

1989 ◽  
Vol 04 (28) ◽  
pp. 2713-2717 ◽  
Author(s):  
I.L. BUCHBINDER ◽  
S.D. ODINTSOV ◽  
O.A. FONAREV
Keyword(s):  
Gravitational Field ◽  
Space Time ◽  
Coupling Constants ◽  
Nonminimal Coupling ◽  
Grand Unification Theory ◽  
Effective Coupling ◽  
Curved Space ◽  
Strong Gravitational Field ◽  
Renormalization Group Equations ◽  
The One

The one-loop renormalization group equations for effective coupling constants corresponding to parameters of nonminimal coupling of scalars and gravitational field in E6 asymptotically free grand unification theory in curved space-time are obtained. The behavior of these effective coupling constants in strong gravitational field is investigated. In strong gravitational field, these effective coupling constants infinitely rise.

4. Gravitational waves

2017 ◽  
pp. 46-57
Author(s):  
Timothy Clifton
Keyword(s):  
Gravitational Field ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Laser Interferometer ◽  
Space Time ◽  
Binary Pulsar ◽  
Set Up ◽  
The Waves

As stars collapse they eject huge amounts of mass and energy; their gravitational field changes rapidly and, therefore, so does the curvature of the space-time around them. If the curvature of space-time is pushed out of equilibrium, by the motion of mass or energy, this disturbance travels outwards as waves. ‘Gravitational waves’ explains the effect of a gravitational wave: in a binary pulsar, the waves carry energy away from the system so that the two neutron stars slowly circle in towards each other. Gravitational waves were first detected in 2015 by the Laser Interferometer Gravitational-Wave Observatory in America. There are also plans to set up a detector in space.

Sign in / Sign up

Export Citation Format

Share Document