The Cuckoo search algorithm is a recent addition to metaheuristic techniques. It simulates the breeding behaviour of certain cuckoo species into a numerical optimization technique. Cuckoo birds lay their eggs in the nests of other host birds so that their chicks when hatched can be nurtured by the host birds. The optimum design algorithm presented for moment resisting steel frames is based on t...

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...

In a previous paper we formulated a set of necessary conditions for the spherically symmetric weakly charged dust to avoid Big Bang/Big Crunch, shell crossing and permanent central singularities. However, we did not discuss the properties of the energy density, some of which are surprising and seem not to have been known up to now. A singularity of infinite energy density does exist – it is a p...

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...