Recent content by yiannis235

I like the example you gave...i also like string theory.I think we can gain a lot from studies of both theories.but i also strongly believe that physics is an experimental science(although i am a theorist).If we don't see any of these things in the ''lab'' it will remain unclear what is the real...

Hi Ben!I also work in theoretical high energy physics!I agree with you (although there are far fewer people working in LPG and reasonably their progress is slower).Since the forum is read by non physicists as well i just wanted to mention that they shouldn't think string theory as a complete...

Be careful though.String theory is a candidate to unify all forces and far from having done this already.

In a sense everything is relativistic.(of course the relativistic effects for particles with very small velocity comparing to c are very small).it depends how precise one wants to be.the classical energy (p^2/2m) can be obtained from the relativistic energy expanding for a small veloity.then you...

This was the interpretation by feynman and stuckelberg and also the beginning in a sense of feynman diagrams.Dirac's theory also predicted particles with negative energy.People at that time couldn't understand what that could mean.You have to think just like when a negative charge is leaving is...

vev is the vacuum expectation value as mentioned before,but breaks the symmetry only when taking non zero value

I don't exactly agree with this reply although you have a point.my disagreement is in the example of quarks.yes we can not have them freely moving(at least so far)..however,in feynman diagrams that i assume you know you can calculate processes with quarks being external particles and therefore...

You have to learn the meaning of off-shell and on-shell particles.A particle on the mass shell satisfies the relation p^2=m^2 where p and m are the momentum and the mass of the particle.The propagator of a particle is 1/(p^2-m^2) (the denominator at least).virtual particles are of-shell and...