Kinetic theory in general relativity

[rubecuber]

need some help clarifying kinetic theory (what it means, equations associated with it and what it pertains to, limits etc...)
thanks,
rubecuber

 

[robphy]

As a start, you might look at Ch 2 of
http://www.pma.caltech.edu/Courses/ph136/yr2006/text.html

later,
take a peak at http://books.google.com/books?id=vC...ts=v1rrDicEzy&sig=k0r_TnbeHQUdwNEf0MEIw0VmPms
and possibly track down articles like
http://books.google.com/books?hl=en...ts=v1rrDicFAC&sig=yCKMsy0ATMN-G856Gb7P2zwPY-k

 

[Entropia]

Kinetic theory is a branch of physics that describes the behavior of particles in a gas or liquid based on their motion and interactions with each other. In general relativity, this theory is extended to include the effects of gravity and the curvature of spacetime.

The key equation associated with kinetic theory is the Boltzmann equation, which describes the evolution of the distribution function of particles in a gas or liquid. This equation takes into account the velocities and positions of individual particles, as well as their interactions with each other. It is a fundamental equation in statistical mechanics and is used to calculate thermodynamic quantities such as pressure, temperature, and entropy.

In the context of general relativity, kinetic theory is used to study the behavior of matter in the presence of strong gravitational fields. This is particularly important in astrophysical scenarios such as black holes, neutron stars, and the early universe. The effects of gravity on the motion and interactions of particles can significantly alter their behavior and lead to new phenomena.

One of the key limits of kinetic theory in general relativity is the assumption of a classical, non-quantum description of particles. This may not accurately describe the behavior of matter at very small scales, such as in the early universe or near the event horizon of a black hole. In these extreme scenarios, a quantum description of matter is needed, which is beyond the scope of kinetic theory.

In summary, kinetic theory in general relativity extends the classical description of particles in a gas or liquid to include the effects of gravity. It is a useful tool for studying the behavior of matter in extreme gravitational environments, but has its limitations in the quantum realm.