Feb
6
comment A dictionary of string - standard physics correspondences
I don't know the field, hence cannot tell where to draw the limit. Everything that would add insight without much technicality would be welcome.
Feb
2
comment A dictionary of string - standard physics correspondences
@LubošMotl: When I asked the question I thought there might be many entries. So I was disappointed of the answer. I want to know what of string theory can be understood on an intuitive but still technical level, with a background in general relativity, quantum fields and conformal fields, but without background knowledge from string theory.
Jan
25
answered Mass gap for photons
Jan
25
revised What is a mass gap?
added a reference
Jan
25
answered Energy spectrum, mass spectrum, and mass gap
Jan
25
comment Energy spectrum, mass spectrum, and mass gap
The lack of a mass gap goes in all intersting cases together with the existence of a massless particle. These don't have a rest frame. See, e.g., the sections
Jan
22
answered What distinguishes time from space in Quantum Field Theory?
Jan
22
comment Is time continuous?
@Michael: But any discrete structure can be approximated by a continuous structure, and conversely, arbitrarily well, so macroscopic evidence is always ambiguous whith respect to deciding between discrete and continuous. For example, quantum jumps, that were once successfully understood as discrete, can nowadays be continuously resolved so that one can see a gradual ''jump''.
Jan
16
comment Is time continuous?
@Michael: Quantization of radiation energy is, in today's terms, not a phenomenon of discretization - the energy spectrum remains continuous. And all of quantum mechnaics is based on a continuous time!
Jan
6
comment Quantum Field Theory and the Hartree-Fock approximation
@Nick: One creates product states and sums them up.
Jan
4
awarded  Necromancer
Jan
1
comment Quantum Field Theory and the Hartree-Fock approximation
No. Nonproduct states are valid states even in the free case. However, in the free case, they will stay product states under the dynamics, while in the nonfree case they won't. In particular, in the nonfree case, a product state cannot be an exact product state.
Dec
31
awarded  statistical-mechanics
Dec
27
awarded  Enlightened
Dec
27
awarded  Nice Answer
Dec
23
answered Quantum Field Theory and the Hartree-Fock approximation
Dec
13
awarded  Necromancer
Dec
13
comment Quantization of Gravitational Field: Quantization conditions
@ArashArabi: Criticising is easy. Be constructive, and post a clearer and more precise explanation of the reason for the graviton being a spin-2 particle!
Dec
12
revised Quantization of Gravitational Field: Quantization conditions
added references and the reason why I refer to Brunetti et al.
Dec
11
awarded  Revival