Tagged Questions
0
votes
1answer
83 views
Density operator in second quantization
I would want to understand why the density operator in second quantization takes the form:
$$\rho_\sigma(\mathbf{r})=\Psi_\sigma^\dagger(\mathbf{r})\Psi_\sigma(\mathbf{r})?$$
Is this a definition or ...
1
vote
3answers
200 views
EM field quantization
I'm trying to quantize the electromagnetic field by solving the vector potential wave equation, that is:
$$\nabla^{2} \mathbf{A} = \dfrac{1}{c^{2}} \dfrac{\partial ^{2} \mathbf{A}}{\partial t^{2}}, ...
9
votes
3answers
823 views
What does the ordering of creation/annihilation operators mean?
When a system is expressed in terms of creation and annihilation operators for bosonic/fermionic modes, what exactly is the physical meaning of the order in which the operators act?
For example, for ...
1
vote
0answers
256 views
Quantization of Gravitational Field: Quantization conditions
I'm begining to study Quantization of field with the second quantization formalism. I've studied phononic field, electromagnetic field in the vacuum and a generic relativistical scalar field.
I ...
7
votes
2answers
555 views
What does second quantization mean in the context of string theory?
String field theory (in which string theory undergoes "second quantization") seems to reside in the backwaters of discussions of string theory. What does second quantization mean in the context of a ...
21
votes
9answers
2k views
Is a “third quantization” possible?
Classical mechanics: $t\mapsto \vec x(t)$, the world is described by particle trajectories $\vec x(t)$ or $x^\mu(\lambda)$, i.e. the Hilbert vector is the particle coordinate function $\vec x$ (or ...
