The purpose of this review is to discuss recent developments occurring at the interface of cosmology with string and M-theory. We begin with a short review of 1980s string cosmology and the Brandenberger-Vafa mechanism for explaining spacetime dimensionality and then introduce the Pre-Big-Bang scenario (PBB), the work of Hořava-Witten and Lukas, Ovrut and Waldram, and end with a discussion of t...

We show that (massive) D = 10 type IIA supergravity possesses a hidden rigid D 9 ≡ SO(9, 9) symmetry and a hidden local SO(9) × SO(9) symmetry upon dimensional reduction to one (time-like) dimension. We explicitly construct the associated locally supersymmetric Lagrangian in one dimension, and show that its bosonic sector, including the mass term, can be equivalently described by a truncation o...

In her paper ([4]), Janice Glasgow adresses many important advantages that imagery models can offer over sentential models such as predicate logic. In this response, we point out another important advantage of imagery with respect to the formulation of models. Consider the problem of reasoning about placing two-dimensional polygonal “blocks” in a space, illustrated in Figure 1. For purposes suc...

This is a summary of a course given at the Fourth Mexican School on Gravitation and Mathematical Physics on some aspects of PBB cosmology. After introductory remarks the lectures concentrate on some amusing consequences derived from the symmetries of the string theory with respect to such classical concepts as isotropy and homogeneity. The extra dimensions and the symmetries of the M theory are...

This paper shows how a social reasoning mechanism can be used by an agent in order to enhance his adaptation in an open multi-agent system. By open multi-agent system, we mean that new agents can dynamically enter and leave the agency and that some of them can change their current knowledge during execution time. We call adaptation the fact that due to these changes, the agents may be led to ma...

I present a domain-specific architecture targeted for a real-world version of the Blocks World domain called “Real” Blocks World. The architecture design attempts to include the best features of several popular Agent Architecures, while mitigating their weaknesses. Agent functionality is considered in light of environment scenarios, single-agent, and multiagent systems.

This study is to assess PBB in Shiraz municipality. So a questionnaire was issued and a model was proposed to assess the possibility of PBB. Based on SHAH model the study findings concerning the subjects were negative in relation to three authority dimensions namely the authority to assess the performance and human and technical abilities and there is not the authority necessary to execute PBB ...

People acquire new knowledge in various ways and this helps them to adapt to changing environment properly. In this paper, we investigate the interoperation of multiple learning mechanisms within a single system. We extend a cognitive architecture, ICARUS, to have three different modes of learning. Through experiments in a modified Blocks World and a route generation domain, we test and demonst...

We present a formalization of the blocks world on the basis of the situation calculus and circumscription, and investigate its mathematical properties. The main theorem describes the eeect of the circumscription which solves the frame problem in the presence of ramiications. The theorem is quite general, in the sense that it is applicable not only to the blocks world, but to a whole class of do...

In this paper, to compare the situation calculus and event calculus we formulate both as logic programs and prove properties of these by reasoning with their completions augmented with induction. We thus show that the situation calculus and event calculus imply one another. Whereas our derivation of the event calculus from the situation calculus requires the use of induction, our derivation of ...