Strength of gravity in asymptotic safe gravity

  • Context: Undergrad 
  • Thread starter Thread starter kodama
  • Start date Start date
  • Tags Tags
    Gravity Strength
Click For Summary
SUMMARY

The discussion centers on the behavior of gravity in asymptotic safe gravity theories, particularly as mass increases and distance decreases. In classical General Relativity (GR), gravity intensifies infinitely near a black hole's singularity. However, in Loop Quantum Gravity (LQG) and Loop Quantum Cosmology (LQC), gravity becomes repulsive at Planckian densities, suggesting the existence of Planck stars instead of singularities. Asymptotic safe gravity theories propose that gravity may not continue to increase indefinitely, potentially leading to alternative states of matter, such as neutron stars or quark stars, within black holes.

PREREQUISITES
  • Understanding of General Relativity (GR)
  • Familiarity with Loop Quantum Gravity (LQG) and Loop Quantum Cosmology (LQC)
  • Knowledge of asymptotic safety in quantum field theories
  • Basic concepts of black hole physics and singularities
NEXT STEPS
  • Research the implications of asymptotic safe gravity on black hole formation
  • Explore the characteristics of Planck stars in Loop Quantum Gravity
  • Study the differences between asymptotic safety and asymptotic freedom in quantum theories
  • Investigate the properties of fuzz balls in string theory at Planckian densities
USEFUL FOR

The discussion is beneficial for theoretical physicists, cosmologists, and researchers interested in quantum gravity, black hole physics, and the fundamental nature of gravity at extreme densities.

kodama
Messages
1,088
Reaction score
144
in classical GR the strength of gravity increase to infinity as mass increases and distance decrease.

in classical GR a black hole consists of an event horizon, and a singularity of infinite density and point-size inside the black hole.

in LQG/LQC strength of gravity eventually becomes repulsive near Planckian densities leading to predictions of a Planck star at the center of a black hole

in string/m theory gravity results in a fuzz ball at Planckian densities

how does strength of gravity in asymptotic safe gravity behave as mass increases and distance decrease?

does it decrease then becomes repulsive at decreasing distance like color force in QCD which is also asymptotic safe ?

how does this affect predictions of black hole singularities ?

i.e if gravity behaves like gravity in asymptotic safe gravity, what is at the center of a black hole?
 
Physics news on Phys.org
kodama said:
in classical GR the strength of gravity increase to infinity as mass increases and distance decrease.

in classical GR a black hole consists of an event horizon, and a singularity of infinite density and point-size inside the black hole.

in LQG/LQC strength of gravity eventually becomes repulsive near Planckian densities leading to predictions of a Planck star at the center of a black hole

in string/m theory gravity results in a fuzz ball at Planckian densities

how does strength of gravity in asymptotic safe gravity behave as mass increases and distance decrease?

In general, the term "asymptotic safety" means that interaction strength tends to a finite fixed value as distance goes to 0. Thus, a theory with any such finite value (positive, negative or zero) is asymptotically safe.

However, theories with zero strength are usually called "asymptotically free" (as it is a much nicer property). Normally, "asymptotically safe gravity" theories have a non-zero, usually positive, value.
 
nikkkom said:
In general, the term "asymptotic safety" means that interaction strength tends to a finite fixed value as distance goes to 0. Thus, a theory with any such finite value (positive, negative or zero) is asymptotically safe.

However, theories with zero strength are usually called "asymptotically free" (as it is a much nicer property). Normally, "asymptotically safe gravity" theories have a non-zero, usually positive, value.

in LQC gravity goes to zero then becomes repulsive, is this also "asymptotic safety"

so in"asymptotically safe gravity" theories depending on that non-zero, usually positive, value, it's possible either black holes do not form from stellar collapse, or if they do form, something like a neutron star or quark star or new state of matter is inside the black hole, if gravity doesn't continue to grow stronger and isn't able to overcome pauli exclusion principle among fermions, instead of a singularity in classical GR
 

Similar threads

  • · Replies 15 ·
Replies
15
Views
6K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 29 ·
Replies
29
Views
7K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 19 ·
Replies
19
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K