دانلود کتاب شبه بوزون ها و حالات منسجم آنها

Doing research is fun! I like when I find something unclear, and I like more when I understand what is going on. The point is that, quoting George Bernard Shaw, science never solves a problem without creating ten more. For this reason, from time to time, I force myself to stop considering new problems and I try to spend some time to summarize what I have done so far. And the best way to clarify the state of the art is putting all results together, giving them the form of a selfcontained book. However, on the way, sometimes I meet crossroads leading me in different directions with respect to those I had in mind at the beginning of my adventure. This is particularly true for these notes,which, inmy original idea, should have been a short paper on a very specific topic, the Baker-Campbell-Hausdorff formula for pseudo-bosonic operators. While preparing this paper I realized that, in connection with this formula, there was much more to say, and from several points of view: mathematical details are relevant, but also physical applications are of interest, of course. Then I started to add material to the original manuscript, and the new material required more and more discussions, lemmas, theorems, and convergence tests. And, at a certain stage, it became evident that I was no more writing a (now, long) paper, but something different. For this reason, I also added some introductory material in Chaps. 2 and 3, in the attempt to make the final result sufficiently self-contained. The result is a book which is essentially about several aspects of ladder operators of a special kind. These are deformed versions of the lowering and raising bosonic operators all people working in quantum mechanics know very well. I will discuss the sets of vectors on which they act as ladders, some appearances in quantum mechanics, and the coherent states connected to these deformed annihilation operators. I will also discuss extensions to distributions of this framework, and the use of my particular coherent states in the computation of transition probabilities. I really hope that reading these notes will be interesting, and maybe inspiring, to you. In the meantime, enjoy the reading!