scholarly journals Self-similar scalar field collapse: Naked singularities and critical behavior

1995 ◽  
Vol 51 (8) ◽  
pp. 4168-4176 ◽  
Author(s):  
Patrick R. Brady
Keyword(s):  
Scalar Field ◽  
Critical Behavior ◽  
Naked Singularities ◽  
Self Similar

scholarly journals NAKED SINGULARITIES IN THREE-DIMENSIONS

2003 ◽  
Vol 12 (05) ◽  
pp. 791-799
Author(s):  
G. OLIVEIRA-NETO
Keyword(s):  
Scalar Field ◽  
Analytical Solution ◽  
Cosmic Censorship ◽  
The Self ◽  
Three Dimensions ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Naked Singularities ◽  
Asymptotically Flat ◽  
Self Similar

We study an analytical solution to the Einstein's equations in (2+1)-dimensions, representing the self-similar collapse of a circularly symmetric, minimally coupled, massless, scalar field. Depending on the value of certain parameters, this solution represents the formation of naked singularities. Since our solution is asymptotically flat, these naked singularities may be relevant for the weak cosmic censorship conjecture in (2+1)-dimensions.

scholarly journals SELF-SIMILAR COLLAPSE OF A SCALAR FIELD IN DILATON GRAVITY AND CRITICAL BEHAVIOR

2004 ◽  
Vol 19 (15) ◽  
pp. 2495-2504 ◽  
Author(s):  
STOYTCHO S. YAZADJIEV
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Critical Behavior ◽  
Analytical Models ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Black Hole Mass ◽  
General Relativistic ◽  
Self Similar ◽  
Similar Solutions

We present new analytical self-similar solutions describing a collapse of a massless scalar field in scalar–tensor theories. The solutions exhibit a type of critical behavior. The black hole mass for the near critical evolution is analytically obtained for several scalar–tensor theories and the critical exponent is calculated. Within the framework of the analytical models we consider it is found that the black hole mass law for some scalar–tensor theories is of the form M BH =f(p-p cr )(p-p cr )γ which is slightly different from the general relativistic law M BH = const (p-p cr )γ. The explicit form of the function f depends on the particular scalar–tensor theory.

Disappearance of Black Hole Criticality in Semiclassical General Relativity

1997 ◽  
Vol 12 (10) ◽  
pp. 709-718 ◽  
Author(s):  
Takeshi Chiba ◽  
Masaru Siino
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Scalar Field ◽  
Critical Phenomena ◽  
Equations Of Motion ◽  
Quantum Effects ◽  
Hole Formation ◽  
Trace Anomaly ◽  
Self Similar ◽  
Similar Solutions

We investigate the quantum effects on the so-called critical phenomena in black hole formation. Quantum effects of a scalar field are treated semiclassically via a trace anomaly method. It is found that the demand of regularity at the origin implies the disappearance of the echo. It is also found that semiclassical equations of motion do not admit continuously self-similar solutions. The quantum effects would change the critical solution from a discretely self-similar one to a solution without critical phenomena.

scholarly journals SOLVING NONPERTURBATIVE FLOW EQUATIONS

1995 ◽  
Vol 10 (31) ◽  
pp. 2367-2379 ◽  
Author(s):  
J. ADAMS ◽  
N. TETRADIS ◽  
J. BERGES ◽  
F. FREIRE ◽  
C. WETTERICH ◽  
...  
Keyword(s):  
Field Theory ◽  
Scalar Field ◽  
Critical Behavior ◽  
Good Accuracy ◽  
Three Dimensional ◽  
Scale Dependence ◽  
Flow Equation ◽  
Flow Equations ◽  
Approximate Form ◽  
Average Action

Nonperturbative exact flow equations describe the scale dependence of the effective average action. We present a numerical solution for an approximate form of the flow equation for the potential in a three-dimensional N-component scalar field theory. The critical behavior, with associated critical exponents, can be inferred with good accuracy.

scholarly journals Asymptotically Friedmann self-similar scalar field solutions with potential

2008 ◽  
Vol 77 (12) ◽  
Author(s):  
Masanori Kyo ◽  
Tomohiro Harada ◽  
Hideki Maeda
Keyword(s):  
Scalar Field ◽  
Self Similar

scholarly journals Geodesic motion near self-gravitating scalar field configurations

2019 ◽  
Vol 27 (3) ◽  
pp. 231-241
Author(s):  
Ivan M. Potashov ◽  
Julia V. Tchemarina ◽  
Alexander N. Tsirulev
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Circular Orbit ◽  
Naked Singularity ◽  
Schwarzschild Black Hole ◽  
Null Geodesics ◽  
Naked Singularities ◽  
Test Particles ◽  
Stable Circular Orbit ◽  
Innermost Stable Circular Orbit

We study the geodesics motion of neutral test particles in the static spherically symmetric spacetimes of black holes and naked singularities supported by a selfgravitating real scalar field. The scalar field is supposed to model dark matter surrounding some strongly gravitating object such as the centre of our Galaxy. The behaviour of timelike and null geodesics very close to the centre of such a configuration crucially depends on the type of spacetime. It turns out that a scalar field black hole, analogously to a Schwarzschild black hole, has the innermost stable circular orbit and the (unstable) photon sphere, but their radii are always less than the corresponding ones for the Schwarzschild black hole of the same mass; moreover, these radii can be arbitrarily small. In contrast, a scalar field naked singularity has neither the innermost stable circular orbit nor the photon sphere. Instead, such a configuration has a spherical shell of test particles surrounding its origin and remaining in quasistatic equilibrium all the time. We also show that the characteristic properties of null geodesics near the centres of a scalar field naked singularity and a scalar field black hole of the same mass are qualitatively different.

Sign in / Sign up

Export Citation Format

Share Document