Type-II super-Backlund transformation and integrable defects for the N=1 super sinh-Gordon model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

N=1 super sinh-Gordon model with defects revisited

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Margaret Mae Bryant Papers - Accession 21

This collection consists of Dr. Bryant’s professional and organizational files, biographical data, correspondence, and speeches. Most of the material relates to her publishing efforts, her work as a faculty member at Brooklyn College, and her involvement with professional organizations, especially the New York branch of the American Association of University Women. Most of the material extends form 1950-1975. A list of the more prominent individuals who corresponded with Margaret Bryant has been included as an appendix to the inventory. (For more extensive and comprehensive list of correspondents, see the list included in the collection control file.)

New path integral simulation algorithms and their application to creep in the quantum sine-Gordon chain

A path integral simulation algorithm which includes a higher-order Trotter approximation (HOA)is analyzed and compared to an approach which includes the correct quantum mechanical pair interaction (effective Propagator (EPr)). It is found that the HOA algorithmconverges to the quantum limit with increasing Trotter number P as P^{-4}, while the EPr algorithm converges as P^{-2}.The convergence rate of the HOA algorithm is analyzed for various physical systemssuch as a harmonic chain,a particle in a double-well potential, gaseous argon, gaseous helium and crystalline argon. A new expression for the estimator for the pair correlation function in the HOA algorithm is derived. A new path integral algorithm, the hybrid algorithm, is developed.It combines an exact treatment of the quadratic part of the Hamiltonian and thehigher-order Trotter expansion techniques.For the discrete quantum sine-Gordon chain (DQSGC), it is shown that this algorithm works more efficiently than all other improved path integral algorithms discussed in this work. The new simulation techniques developed in this work allow the analysis of theDQSGC and disordered model systems in the highly quantum mechanical regime using path integral molecular dynamics (PIMD)and adiabatic centroid path integral molecular dynamics (ACPIMD).The ground state phonon dispersion relation is calculated for the DQSGC by the ACPIMD method.It is found that the excitation gap at zero wave vector is reduced by quantum fluctuations. Two different phases exist: One phase with a finite excitation gap at zero wave vector, and a gapless phase where the excitation gap vanishes.The reaction of the DQSGC to an external driving force is analyzed at T=0.In the gapless phase the system creeps if a small force is applied, and in the phase with a gap the system is pinned. At a critical force, the systems undergo a depinning transition in both phases and flow is induced. The analysis of the DQSGC is extended to models with disordered substrate potentials. Three different cases are analyzed: Disordered substrate potentials with roughness exponent H=0, H=1/2,and a model with disordered bond length. For all models, the ground state phonon dispersion relation is calculated.

Dispersive wave solutions of the klein-gordon equation in cosmology

L'equazione di Klein-Gordon descrive una ampia varietà di fenomeni fisici come la propagazione delle onde in Meccanica dei Continui ed il comportamento delle particelle spinless in Meccanica Quantistica Relativistica. Recentemente, la forma dissipativa di questa equazione si è rivelata essere una legge di evoluzione fondamentale in alcuni modelli cosmologici, in particolare nell'ambito dei cosiddetti modelli di k-inflazione in presenza di campi tachionici. L'obiettivo di questo lavoro consiste nell'analizzare gli effetti del parametro dissipativo sulla dispersione nelle soluzioni dell'equazione d'onda. Saranno inoltre studiati alcuni tipici problemi al contorno di particolare interesse cosmologico per mezzo di grafici corrispondenti alle soluzioni fondamentali (Funzioni di Green).

L'adulterio come strumento sociale: confronto tra Anna Karenina e Lady Chatterley

Lo scopo di questo lavoro è confrontare due opere, Anna Karenina di Lev Tolstoj e L’amante di Lady Chatterley di David Herbert Lawrence e dimostrare che essi non hanno in comune solo il tema dell’adulterio, ma anche e soprattutto l’averlo inteso come strumento di ribellione sociale. In Tolstoj troviamo l’adulterio censurato nel corso della narrazione, poiché esso viene condannato sia dalla società che dall’autore stesso, che aveva come intento dare una lezione morale. Lawrence invece esalta e descrive l’adulterio, poiché nel suo caso diventa lo strumento di scoperta dell’amore vero e di ritorno al primitivismo a dispetto della civiltà industrializzata. Quindi, pur appartenendo a due epoche diverse e a due società con differenti visioni circa matrimonio e famiglia, le due eroine sono similari per il coraggio che dimostrano nell’andare contro le rispettive società.

Successful treatment of childhood high-risk hepatoblastoma with dose-intensive multiagent chemotherapy and surgery: final results of the SIOPEL-3HR study

The primary objective was to determine the efficacy of a newly designed preoperative chemotherapy regimen in an attempt to improve the cure rate of children with high-risk hepatoblastoma.