A teoria do Big Bang corresponde ao modelo explicativo início Universo a partir de um ponto (singularidade) elevada densidade e temperatura que começa expandir- se, criando-se o espaço-tempo. Sendo seguido pelo período inflação cósmica, dominado pela radiação outro matéria (principalmente escura) até momento atual, por uma energia escura, permite explicar história nosso observável. O é bem test...

A fractional order PID (FOPID) control technique for automatic generation (AGC) in a multi-area power system is presented this study. To create reliable controller, variety of strategies were used. The load frequency (LFC) problem implementing different transactions, such as bilateral and Poolco are investigated here. Because any scheme’s performance only good its parameters, the parameters des...

It is known that certain AdS boundary conditions allow smooth initial data to evolve into a big crunch. To study this type of cosmological singularity, one can use the dual quantum field theory, where the non-standard boundary conditions are reflected by the presence of a multi-trace potential unbounded below. For specific AdS4 and AdS5 models, we provide a D-brane (or M-brane) interpretation o...

To explain current observations the early universe must have been incredibly flat and homogeneous. Tiny density fluctuations must have been present to seed large scale structure. Any viable model of the universe has to explain these cosmological puzzles and be able to generate a nearly flat spectrum of density perturbations, as required by microwave background data. Inflation is a period of acc...

In general relativity space-time ends at singularities. The big bang is considered as the Beginning and the big crunch, the End. However these conclusions are arrived at by using general relativity in regimes which lie well beyond its physical domain of validity. Examples where detailed analysis is possible show that these singularities are naturally resolved by quantum geometry effects. Quantu...

We use D-instantons to probe the geometry of Misner universe, and calculate the world volume field theory action, which is of the 1+0 dimensional form and highly nonlocal. Turning on closed string tachyons, we see from the deformed moduli space of the D-instantons that the spacelike singularity is removed and the region near the singularity becomes a fuzzy cone, where space and time do not comm...

We study an exact model of string theory propagating in a space–time containing regions with closed time–like curves (CTCs) separated from a finite cosmological region bounded by a Big Bang and a Big Crunch. The model is an non–trivial embedding of the Taub–NUT geometry into heterotic string theory with a full conformal field theory (CFT) definition, discovered over a decade ago as a heterotic ...

We use D-instantons to probe the geometry of Misner universe, and calculate the world volume field theory action, which is of the 1+0 dimensional form and highly non-local. Turning on closed string tachyons, we see from the deformed moduli space of the D-instantons that the spacelike singularity is removed and the region near the singularity becomes a fuzzy cone. The infinite past is now causal...