Understanding Entropy and Gravity in Quantum Field Theory: A Beginner's Guide

[M. next]

I read a sentence that says if a spherical volume in placed in a quantized space then the maximum entropy of the system can be calculated and it after simple steps found to be:
S~V where V is the volume of the spherical volume.

"Then the author said: Each local quantum field theory(with UV cut-off, in this case the grid) will give rise to an entropy that scales in that way. But, once gravity comes into play, this will no longer be so. Gravity gives rise to so-called dimensional reduction."

Can someone explain to me (because I know nothing about quantum field theory what was meant by the quoted 2 sentences above)? Thank you in advance

 

[Jilang]

I would take it to mean that it becomes proportional to the surface area rather than the volume.

 

[M. next]

Which sentence are you talking about? I guess the second one. If so, what does this one mean "Each local quantum field theory(with UV cut-off, in this case the grid) will give rise to an entropy that scales in that way."

What UV cut off? "In that way"? What way?

 

[atyy]

@M. next, please give the exact reference (author, title, journal, issue, page number, year published, and link to free version if possible) of the paper you are citing. At the moment, I think hardly anyone can understand your question because it is so bereft of context.

Incidentally, I believe the rule in all subforums of Physics Forums, except for "Beyond the Standard Model" is that papers discussed must have been published in peer reviewed journals, or come from sources of similar repute. Reputation does not imply correctness, and plenty of good stuff appears elsewhere, but because there is so much rubbish out there, I believe this is the rule that is used at PF.

 

[Jilang]

I agree with atyy, it would be helpful to see the full context.