Potential pharmaceutical derivatives of β-aminoethylpiperazine

This thesis is concerned with the design and preparation of certain organic compounds which are expected to have medicinal properties. A discussion will be given which has essentially a two-fold purpose. The first is to discuss somewhat briefly the currently accepted method of rug design, and the second to show to what extent this method has been followed in the design of the compounds prepared

Effective growth of matter density fluctuations in the running LCDM and LXCDM models

We investigate the matter density fluctuations \delta\rho/\rho for two dark energy (DE) models in the literature in which the cosmological term \Lambda is a running parameter. In the first model, the running LCDM model, matter and DE exchange energy, whereas in the second model, the LXCDM model, the total DE and matter components are conserved separately. The LXCDM model was proposed as an interesting solution to the cosmic coincidence problem. It includes an extra dynamical component, the "cosmon" X, which interacts with the running \Lambda, but not with matter. In our analysis we make use of the current value of the linear bias parameter, b^2(0)= P_{GG}/P_{MM}, where P_{MM} ~ (\delta\rho/\rho)^2 is the present matter power spectrum and P_{GG} is the galaxy fluctuation power spectrum. The former can be computed within a given model, and the latter is found from the observed LSS data (at small z) obtained by the 2dF galaxy redshift survey. It is found that b^2(0)=1 within a 10% accuracy for the standard LCDM model. Adopting this limit for any DE model and using a method based on the effective equation of state for the DE, we can set a limit on the growth of matter density perturbations for the running LCDM model, the solution of which is known. This provides a good test of the procedure, which we then apply to the LXCDM model in order to determine the physical region of parameter space, compatible with the LSS data. In this region, the LXCDM model is consistent with known observations and provides at the same time a viable solution to the cosmic coincidence problem.Comment: LaTeX, 38 pages, 8 figures. Version accepted in JCA

Cosmological Constant Problems and Renormalization Group

The Cosmological Constant Problem emerges when Quantum Field Theory is applied to the gravitational theory, due to the enormous magnitude of the induced energy of the vacuum. The unique known solution of this problem involves an extremely precise fine-tuning of the vacuum counterpart. We review a few of the existing approaches to this problem based on the account of the quantum (loop) effects and pay special attention to the ones involving the renormalization group.Comment: 12 pages, LaTeX, based on the on the talk at IRGAC-2006 (Barcelona, July 11-15, 2006), misprints corrected, comment on anthropic approach modified, some references added, accepted in Journal of Physics

Princeton Conference Festschrift 250th Birthday on Critical Problems in Physics

The past century has seen fantastic advances in physics, from the discovery of the electron, x-rays, and radioactivity, to the era of incredible solid state devices, computers, quarks and leptons, and the standard model. But what of the next? Many scientists think we are on the threshold of an even more exciting new era in which breakthroughs in a startling variety of directions will produce significant changes in our understanding of the natural world. In this book, a group of eminent scientists define and elaborate on these new directions. Ed Witten and Frank Wilczek discuss string theory and the future of particle physics; Donald Perkins describes the search for neutrino oscillations; Alvin Tollestrup reveals dreams of a muon collider at Fermilab to probe the heart of “elementary” particles; and Robert Palmer anticipates a new generation of particle accelerators. Thibault Damour reviews classical gravitation and the relevant new high-precision experiments; Kip Thorne describes the exciting future for gravitational wave astronomy; and Paul Steinhardt examines the recent breakthroughs in observational cosmology and explains what future experiments might reveal. James Langer explores nonequilibrium statistics and relates it to the origins of complexity; Harry Swinney takes an experimentalist’s view of the emergence of order in seemingly chaotic systems; and John Hopfield describes an extremely unusual dynamical system — the human brain. Bruce Hillman, M. D., discusses the recent developments in imaging techniques that have brought about outstanding advances in medical diagnostics. T.V. Ramakrishnan looks at high-temperature superconductors, which could eventually revolutionize the solid-state technology on which society is already highly dependent