Inside a closed many-body system undergoing the unitary evolution, small partition of whole exhibits local relaxation. If total degrees freedom is large but finite number, such relaxation would come across recurrence after certain time, namely, dynamics suddenly appears random well-ordered oscillatory decay process. It found in this paper, among collection N two-level systems (TLSs), one TLS in...

Motivated by the generation of polynomial loop invariants of computer programs, we study P -solvable recurrences. While these recurrences may contain non-linear terms, we show that the solutions of any such relation can be obtained by solving a system of linear recurrences. We also study invariant ideals of P -solvable recurrences (or equivalently of while loops with no branches). We establish ...

craniospinal irradiation plus posterior fossa boost (cs1) is the standard modality of post-operative treatment of patient with medulloblastoma, but considering the technical difficulties and limited facilities, often whole- brain irradiation plus posterior fossa boost (wbi) had been used in our institution until 1991. tust a retrospective study was undertaken to compare the patients treated by ...

We study numerically the statistics of Poincaré recurrences for the Chirikov standard map and the separatrix map at parameters with a critical golden invariant curve. The properties of recurrences are analyzed with the help of a generalized Ulam method. This method allows us to construct the corresponding Ulam matrix whose spectrum and eigenstates are analyzed by the powerful Arnoldi method. We...