All Questions
Tagged with quantum-field-theory statistical-mechanics
120
questions with no upvoted or accepted answers
57
votes
0
answers
1k
views
Systematic approach to deriving equations of collective field theory to any order
The collective field theory (see nLab for a list of main historical references) which came up as a generalization of the Bohm-Pines method in treating plasma oscillations often used in the study of ...
Zoran Škoda
9
votes
1
answer
889
views
Temperature in the Hamiltonian limit
There is a well known connection between statistical mechanics in D spatial dimensions and quantum field theory in D-1 spatial dimensions. Changing the temperature in statistical mechanics corresponds ...
- 8,815
8
votes
0
answers
145
views
Does the Standard Model plasma develop a spontaneous magnetisation at finite temperature?
Reference: arXiv:1204.3604v1 [hep-ph] Long-range magnetic fields in the ground state of the Standard Model plasma.
Alexey Boyarsky, Oleg Ruchayskiy, Mikhail Shaposhnikov.
The authors of this paper ...
- 16.6k
7
votes
0
answers
125
views
Slowest possible correlation decay in classical lattice models
Consider lattice models in classical statistical mechanics, like the Ising model, specified by the Gibbs ensemble of a (real-valued) local lattice Hamiltonian. What's the slowest that correlation ...
- 935
7
votes
0
answers
3k
views
Numerical problem in solving the Bogoliubov de Gennes equations- methods to solve?
I am trying to solve an assignment on solving the Bogoliubov de Gennes equations self-consistently in Matlab. BdG equations in 1-Dimension are as follows:-
$$\left(\begin{array}{cc}
-\frac{\hbar^{2}}...
- 377
7
votes
0
answers
749
views
Stability of the vacuum state of interacting quantum fields
"Stability" is generally taken to be the justification for requiring that the spectrum of the Hamiltonian should be bounded below. The spectrum of the Hamiltonian is not bounded below for thermal ...
- 9,948
6
votes
0
answers
84
views
Why one-particle irreducible functional is closely related to pressure (electroweak phase transition)?
Consider the following system: the SM lagrangian somewhat below the EW transition, where we keep only bilinear terms, only the heaviest fermion -- $t$-quark, and plus the potential terms for a VEV $\...
- 8,901
6
votes
0
answers
179
views
Physical examples of log CFTs
There are examples of CFTs having correlators with logarithms. What are the examples of physical systems exhibiting such logarithmic behaviour (particularly in $d>2$ dimensions)?
- 1,542
6
votes
0
answers
397
views
Renormalization, Phase transitions and order parameters
Renormalization is the phenomenon for which, once a finite number of parameters, which are the couplings with positive-mass dimension, are fixed, then it is possible to express any $n$-point ...
- 2,060
6
votes
2
answers
3k
views
Bose-Einstein condensation and phase transition
I would like to ask the following question for which I cannot find a definite answer in the literature.
Of what ORDER is the phase transition leading to Bose-Einstein condensation for a ideal and ...
- 1,323
5
votes
0
answers
276
views
Absence of Symmetry Breaking in 1D Ising Model--Continuum Version
I have seen arguments for why there is no symmetry breaking in the 1D Ising model--for example, using the transfer matrix method to explicitly solve the model, and another of energy-entropy arguments ...
- 642
5
votes
0
answers
292
views
Some questions about the large-N Gross-Neveu-Yukawa model
Consider the following action with a fermionic field $\psi$ and a scalar field $\sigma$,
$S = \int d^dx \{ -\bar{\psi}(\gamma^\mu \partial_\mu +\sigma )\psi + \Lambda^{d-4}[ \frac{(\partial_\mu \...
- 4,619
4
votes
0
answers
109
views
What is the relationship between the renormalization schemes in quantum field theory and statistical field theory
Consider the $\phi^4$ theory for example.
In QFT, we do renormalized perturbation theory by defining the theory at a particular scale, see for example, eq. 12.30 of Peskin and Schroeder:
Then we can ...
- 51
4
votes
0
answers
60
views
Thermodynamic free energy of interacting system
This question concerns an interacting system's thermodynamic free energy $\Omega$. Generally speaking, The action $S$ for an interacting system has the following form:
\begin{equation}
S(\phi,\psi) = ...
- 2,038
4
votes
0
answers
128
views
Is the path integral emergent?
I have recently read a couple of papers on lattice QCD and found that there is a well-established connection between Boltzmann distribution and the path integral in QFT (disclaimer: I am not a huge ...
