Now showing items 1-5 of 5
A geometric approach to cosmological boundary conditions
(2015-06-09) [Tese de doutorado]
The observed T-asymmetry of macroscopic physics is traced back to the extremely low entropy conﬁguration of the early universe. Although matter was very hot and with a uniform temperature at that stage, the gravitational ...
Equações de Painlevé mistas e modelo PIII-PV simétrico
(2015-03-31) [Tese de doutorado]
This thesis studies the connection among integrable models and Painlev'e equations. We begin by extending the modiﬁed truncation approach in order to ﬁnd B¨acklund transformations for the mKdV-Liouville hierarchy and its ...
Open-closed superstring amplitudes using vertex operators in AdS5xS5
(2015-05-12) [Tese de doutorado]
In this thesis, a particular superstring scattering amplitude involving one closed string and N open string vertex operators in AdS5 ×S5 is studied in detail, usingthe pure-spinor formalism. After reviewing some background ...
Eletrodinâmica quântica generalizada a la teoria de perturbação causal
(2015-03-30) [Tese de doutorado]
In this thesis, we will present a perturbative research of the Generalized Quantum Electrodynamics (GQED4) within the approach of the Causal Perturbation Theory (TPC). With this purpose, we ﬁrst make a review of the basics ...
Transformações de Bäcklund para hierarquias integráveis abelianas
(2015-04-09) [Tese de doutorado]
We study the construction of integrable hierarchies. These hierarchies have inﬁnite equations of motion which arise from the same algebraic structure, and, as a consequence, we can ﬁnd simultaneously and systematically its ...