Recent content by sadegh4137

Hi i want to find propagator of inverse harmonic oscillator to find time dependent wave function, but I can't have any ideas about this. Is it possible to help me to find it Thanks

My question is clear. I want to find a way to calculate volume element of null hypersurface. Isn't it? In Poisson's book,there is a way to find out directed volume element. In this book, there is a little description about volume element of null hypersurface. OM, It was better to tell what I...

exactly i Studied this section of Poisson's book , but here he defined a directed volume element I don't know how to calculate volume element exactly.

how can i do it? is it possible to introduce a book or an article for more detail? I studied Advanced General Relativity By Eric Poisson. In this book, there is a few material.

hi every body Consider we have a null hypersurface. how we can calculate volume element on it?

I read some text to find it's definition Is it possible to tell me it's definition? I read below statements about local and global geometry and I didn't understand it. is it possible tell me it. "If M ( a manifold) has a trivial topology, a single neighborhood can be extended globally...

I read this article!

HI I study some thing about fierz and paulli conditions In massive gravity and Higher spin particle, what's difference between them? the conditions in massive gravity and higher spin are similar. are they related to them? thanks

i couldn't understand you! can you explain it for me more please. thanks

hi i read an article by S.carlip about quantum gravity, arXiv:gr-qc/0108040v1 , in this article carlip stated: why we need quantum gravity what's problems of quantum gravity and two ways of quantization of GR. I couldn't realize some clues in section of "the problems of quantum gravity"...

what's exactly definition of coherent state?

why! isn't definition of coherent state that the states |a> defined by a|\alpha>=\alpha|\alpha> , <\alpha|\alpha>=1 and there is a theorem that say coherent states have a minimum uncertainty relation

hi i read some text about causality and determinism, but i can't exactly distinguish between them. what's really difference between them? does not quantum mechanics respect one of them? i read this phrase in article of S.Carlip about quantum gravity "Quantum field theory includes...

why we shouldn't create a superposition of fermions? i can't understand that what is relationship between coherent state and superposition of fermions! is it possible to explain it for me? thanks.

hi i know what is coherent state, but i read this text in an article and i don't understand this " if we wish to describe long range macroscopic forces, only bosonic fields will do, since fermionic fields cannot build up classical coherent states. " can you explain it for me, how...