Recent content by extranjero

I am asking you to include this example into a future book, because some people (not even a student, but scientist who published in PRB) has a big difficulties with this. You can see the 2 year debates and arguments on this problem here...

I know it, but in the anyway, it will be good to find this quite simple thing literally printed in a book (there is an old debate about this problem with my friend and he ask a proof in a book).

Hi, usually, when we talk about quantum quench dynamics we assume situation when Hamiltonian of a system has a sudden change from ##H_0## to ##H_1##. System was initially in the ground state (or more generally - eigenstate) of ##H_0##. The interesting dynamics appears when the commutator...

This is the same question as "why do they are somewhere in a space (instead of being nowhere)"? Full description possible when we use extended Hilbert space: not this ##|x_1\rangle,\,|x_2\rangle,\,\dots|x_n\rangle,\,\dots##, but this ##|x_1, \uparrow\rangle,\,|x_1, \downarrow\rangle,\,|x_2...

Oh, I didn't think about the possibility to split "service time". In my consideration coming time is discrete and takes values 0 (at the opening) or 1 (after one "service time" after opening). PS. It seems, the solution in your general case must be a special random generator which outputs the...

This is my funny theory (may be I have found already known things...).Let us assume the following abstract situation. We have a special place where people can get some kind of service (for instance any bureaucratic office). There is only one service clerk who spend a fixed time (we will call it...

This my simple idea can not be published in Nature, so, I publish it here :) (Also, it can be used for getting military grants and in pseudoscience TV shows)

This is the "argument" against my solution:

Thanks. Moderator note: links to external debate removed (It makes no sense to discuss on two different forums simultaneously. If you like, you can insert the arguments against your solution manually, such that we have a common basis for discussion without switching forums. However, since the...

The problem looks very simple. We have a time-dependent Hamiltonian: $$H(t) = B(t)H_0$$, where ##B(t)## is a numerical function, and matrix ##H_0## is time-indpendent. Let us consider: $$B(t) = \begin{cases} 1,&\text{for $0\leq t\leq t_0$}\\ A,&\text{for $t>t_0$.} \end{cases}$$ Also, let us...