1,336 reputation
314
bio website unige.ch/math/folks/velenik
location Geneva, Switzerland
age 43
visits member for 1 year, 1 month
seen 17 mins ago
stats profile views 100

Professor at the Mathematics department of the University of Geneva. Mostly working at the intersection of probability theory and statistical physics.


Oct
6
comment Open boundary condition and Glauber Dynamics
The choice of boundary conditions plays a crucial role in the phase coexistence regime. You should have a look at Martinelli's lecture notes, which are available at imap.ma.utexas.edu/mp_arc/c/97/97-578.ps.gz . There are, of course, more recent works, in particular concerning higher-dimensional systems.
Aug
19
comment Loschmidt's paradox - really a paradox?
No, the resolution of this "paradox" has nothing to do with the H-theorem. See the refs in my comment above.
Jul
11
awarded  Revival
Jun
29
comment Loschmidt's paradox - really a paradox?
No, it is considered irrelevant today. See, e.g., this paper. Of course, this does not imply that the problem of the foundations of statistical physics has been settled (in particular, the proper interpretation of probabilities in the theory).
Jun
22
revised What are the justifying foundations of statistical mechanics without appealing to the ergodic hypothesis?
Added one relevant reference and updated another link (which didn't work anymore)...
Jun
22
comment Recommendations for Statistical Mechanics book
Just in case. Here are the google book pages for the last 2 refs, so that you can have an idea of what is done there and at which level: Ruelle, Georgii.
Jun
21
comment Recommendations for Statistical Mechanics book
Another good (but probably too advanced) book is the "old" book by Ruelle, "Statistical Mechanics - Rigorous Results". If you have the level in maths, and are interested in the mathematical theory of phase transitions for lattice systems, the classical reference is Georgii's "Gibbs measures and phase transitions" (although that's more graduate level stuff).
Jun
21
comment Recommendations for Statistical Mechanics book
A good advanced book that covers in details and with mathematical rigor what you want and much more is Gallavotti's "Statistical Mechanics - a short treatise", which is not so short actually... You can get it from here.
Jun
12
awarded  Enthusiast
Jun
5
comment proving that the free energy is extensive
For a much more detailed argument, see the beautiful paper by Jaynes: bayes.wustl.edu/etj/articles/gibbs.paradox.pdf .
Jun
5
comment proving that the free energy is extensive
No, undistinguishability of particles has nothing to do with that. The point is that the thermodynamical definition of entropy is given up to an arbitrary function of the number of particles (it is defined using a differential relation, with fixed number of particles). So the same is true when you define the entropy in stat. mech., since this is done by analogy with the thermodynamic one (they satisfy the thermodynamic relations). The only reason why you need an N! (or something like $N^N$) is that you want entropy to be extensive. This is an additional assumption, which does not always hold.
Jun
5
comment Lacking of scale and distribution moments
@LubošMotl: of course it's a matter of definitions, but there is at least one good, pragmatic reason to say that the Cauchy distribution does not have an expectation: an iid sequence of such random variables will not satisfy the law of large numbers (the sample mean is again Cauchy-distributed)...
Jun
1
comment What is known about some massive Gaussian models on a lattice?
BTW, if you'd like more informations, or additional references, etc., you should rather contact me by email (the address is indicated on my homepage).
Jun
1
awarded  Editor
Jun
1
revised What is known about some massive Gaussian models on a lattice?
added 92 characters in body
May
31
answered What is known about some massive Gaussian models on a lattice?
May
28
awarded  Supporter
May
25
comment Surface tension of solutions and mixtures
If you want some pointers to some of the information about that topic that can be rigorously extracted in simple Ising-like systems, you can have a look at scholarpedia.org/article/Interface_free_energy . Of course, much more is known (in these "simple" models).
May
4
awarded  Nice Question
May
4
awarded  Nice Answer