531 reputation
26
bio website physicsnapkins.wordpress.com
location Barcelona
age 41
visits member for 2 years, 9 months
seen Jun 22 at 16:07

Jan
19
awarded  Yearling
Dec
9
answered How are physics and computer science getting united?
Jan
19
awarded  Yearling
May
4
awarded  Teacher
May
4
awarded  Nice Answer
May
4
awarded  Student
May
4
awarded  Scholar
May
4
awarded  Nice Question
Jan
31
comment Random bond Ising model and computational efficiency
The basic result, i.e.: that obtaining the random-bond-Ising GS for non-planar lattices is NP-complete, was proved by Barahona in 1982. www.yaroslavvb.com/papers/barahona-on.pdf
Jan
31
comment Reduced density matrices for free fermions are thermal
About the relation to the Fulling-Davies theorem, the link that I see is the following. You only get thermalization when a horizon appears (Rindler, Schwartzschild, etc.), which means that you're tracing out some degrees of freedom: those linked to the regions of spacetime that are now disconnected from you. Thermalization is due to this "tracing out", right?
Jan
31
comment Reduced density matrices for free fermions are thermal
LuboŇ°, thanks for your answer, but it is not enough. Of course, the density matrix will be the logarithm of "something" (unless it has some zero eigenvalues). The fact that this "something" has this particular form is non-trivial for me, and requires more work.
Jan
26
asked Reduced density matrices for free fermions are thermal
Jan
19
awarded  Supporter
Jan
17
answered How can one build a multi-scale physics model of fluid flow phenomena?
Jan
15
comment Analog Hawking radiation
The sonic analogue of Unruh effect is fully classical. You can read more about it in G.E. Volovik's book, "The universe in a helium droplet". The $\hbar$ you mention is merely metaphorical.
Jan
14
answered Readable books on advanced topics
Dec
3
comment Examples of number theory showing up in physics
I wouldn't count it as "engineering". It's more like using physical intuition in order to make a breakthrough in maths. We know the properties the Hilbert-Polya hamiltonian should have, so we whether it might be implemented in a physical system.
Sep
16
accepted Does entropy measure extractable work?
Sep
16
comment Does entropy measure extractable work?
Yes, I see. But still with the Szilard engine example, I'd like to go further. If I know in which side the particle si, I can extract kT ln(2) of work. If I don't know where the particle is, I can get no work. But, what if I have partial knowledge? Is still Shannon's entropy the answer?
Sep
16
asked Does entropy measure extractable work?