The Effective Potential, the Renormalisation Group and Vacuum Stability

We review the calculation of the the effective potential with particular emphasis on cases when the tree potential or the renormalisation-group-improved, radiatively corrected potential exhibits non-convex behaviour. We illustrate this in a simple Yukawa model which exhibits a novel kind of dimensional transmutation. We also review briefly earlier work on the Standard Model. We conclude that, despite some recent claims to the contrary, it can be possible to infer reliably that the tree vacuum does not represent the true ground state of the theory.Comment: 23 pages; 5 figures; v2 includes minor changes in text and additional reference

Similarities Between Corticosteroids

Corticosteroids are a class of potent drugs with important physiological effects on the body. Regular use is linked with common and serious side effects. This paper uses studies to analyze the similarities between various corticosteroids. All drugs in this class are molecules that contain the same steroid backbone and are therefore associated with the same cellular receptor. This results in a comparable mechanism and parallel overall effect in the body. Side effects of corticosteroids are analogous as well. Using the knowledge of physiological changes in the body due to corticosteroids will allow healthcare providers to determine the most effective corticosteroid least likely to cause adverse effects, and treat and monitor the patient accordingly

A BDI Agent Software Development Process

As computer software continues to grow increasingly complex with each passing year, researchers continue to try and develop means to simplify software development. In this thesis, we propose a BDI agent software development process as the next evolution in software development. The goal of this research is to develop a process, which can be used to enable the creation of agent-based systems. This thesis strives to present a practical software development process, which is useful to today\u27s software engineer, by building upon current agent research and proven software engineering practices. Our BDI agent software development process is a systematic process, which enables the decomposition of a system into agents. The Belief-Desire-Intention Model is a fundamental ingredient to our development process. We utilize BDI as a natural method for describing agents in our development process. Our software development process utilizes several forms of use cases, which are useful for defining the architecture of a system in our process. We have also leveraged many other existing software development tools such as CRC cards, patterns and the Unified Development Process. We have made modifications to many of these existing tools so they can be used for agent-based development. These are just some of the tools that provide valuable insight into the development of our BDI agent software development process. In addition to describing our software development process, we will also provide a case study to clarify the description of our BDI agent software development process. Basically, our BDI agent software development process strives to model both the dynamic and static structure of the agents that make up the system. Once we have modeled the stmcture, which makes up the agents in the system the stmcture can then be created in software. l

Abelian Gauge Theory in de Sitter Space

Quantization of spinor and vector free fields in 4-dimensional de Sitter space-time, in the ambient space notation, has been studied in the previous works. Various two-points functions for the above fields are presented in this paper. The interaction between the spinor field and the vector field is then studied by the abelian gauge theory. The U(1) gauge invariant spinor field equation is obtained in a coordinate independent way notation and their corresponding conserved currents are computed. The solution of the field equation is obtained by use of the perturbation method in terms of the Green's function. The null curvature limit is discussed in the final stage.Comment: 10 pages, typos corrected, reference adde

de Sitter Vacua, Renormalization and Locality

We analyze the renormalization properties of quantum field theories in de Sitter space and show that only two of the maximally invariant vacuum states of free fields lead to consistent perturbation expansions. One is the Euclidean vacuum, and the other can be viewed as an analytic continuation of Euclidean functional integrals on $RP^d$. The corresponding Lorentzian manifold is the future half of global de Sitter space with boundary conditions on fields at the origin of time. We argue that the perturbation series in this case has divergences at the origin, which render the future evolution of the system indeterminate without a better understanding of high energy physics.Comment: JHEP Latex, 13 pages, v2. references adde