Early Cosmology and Fundamental Physics

This is a pedagogical introduction to early cosmology and the host of fundamental physics involved in it (particle physics, grand unification and general relativity). Inflation and the inflaton field are the central theme of this review. The quantum field treatment of the inflaton is presented including its out of equilibrium evolution and the use of nonperturbative methods. The observational predictions for the CMB anisotropies are briefly discussed. Finally, open problems and future perspectives in connection with dark energy and string theory are overviewed.Comment: Based on Lectures at the 9th. Chalonge School in Astrofundamental Physics, Palermo, September 2002, NATO ASI. To appear in the Proceedings, N. S'anchez and Yu. Parijskij editors, Kluwe

Advances in String Theory in Curved Backgrounds: A Synthesis Report

A synthetic report of the advances in the study of classical and quantum string dynamics in curved backgrounds is provided, namely: the new feature of multistring solutions; the effect of a cosmological constant and of spacial curvature on classical and quantum strings; classical splitting of fundamental strings;the general string evolution in constant curvature spacetimes;the conformal invariant effects;strings on plane waves, shock waves and spacetime singularities and its spectrum. New developments in string gravity and string cosmology are reported: string driven cosmology and its predictions;the primordial gravitation wave background; non-singular string cosmologies from exact conformal field theories;QFT, string temperature and the string phase of de Sitter space; the string phase of black holes;new dual relation between QFT regimes and string regimes and the 'QFT/String Tango'; new coherent string states and minimal uncertainty principle in string theor

Extreme Energy Cosmic Rays: Bottom-up vs. Top-down scenarii

We present an overview on extreme energy cosmic rays (EECR) and the fundamental physics connected with them. The top-down and bottom-up scenarii are contrasted. We summarize the essential features underlying the top-down scenarii for EECR, namely, the lifetime and the mass {\bf imposed} to the heavy relics whatever they be: topological and non-topological solitons, X-particles, cosmic defects, microscopic black-holes, fundamental strings. An unified formula for the quantum decay rate of all these objects was provided in hep-ph/0202249. The key point in the top-down scenarii is the necessity to {\bf adjust} the lifetime of the heavy object to the age of the universe. The natural lifetimes of such heavy objects are, however, microscopic times associated to the GUT energy scale (sim 10^{-28} sec. or shorter); such heavy objects could have been abundantly formed by the end of inflation and it seems natural they decayed shortly after being formed. The arguments produced to {\bf fine tune} the relics lifetime to the age of the universe are critically analyzed. The annihilation scenario (`Wimpzillas') is analyzed too. Top-down scenarii based on networks of topological defects are strongly disfavored at the light of the recent CMB anisotropy observations. We discuss the acceleration mechanisms of cosmic rays,their possible astrophysical sources and the main open physical problems and difficulties in the context of bottom-up scenarii, and we conclude by outlining the expectations from future observatories like EUSO and where the theoretical effort should be placed.Comment: LaTex, 16 pages, 2 .eps figures. The annihilation scenario (Wimpzillas) is included and the discussion on gamma ray bursts improved. Based on lectures at the Fourth International Workshop on `New Worlds in Astroparticle Physics' in Faro, Portugal, September 2002, at the 9th Course on Astrofundamental Physics of the Chalonge School, Palermo, Italia, September 2002 and at the SOWG EUSO meeting, Roma, Italia, November 200

Antibacterial biocomposite materials based on essential oils embedded in sol–gel hybrid silica matrices

For the design of antibacterial materials comprising hybrid silica-containing plant oils capable of performing a controlled release of essential oil components, tests of lemongrass, citronella, basil, rosemary, eucalyptus, tea tree, lavender, clove and cinnamon against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Micrococcus luteus showed the essential oil of cinnamon to have the greatest antimicrobial activity. Hybrid organic–inorganic silica materials functionalized with methyl groups (methyl/Si, molar proportions 0.04–1.00), prepared with a sol–gel method, served as host matrices for the essential oil of cinnamon. The antibacterial and release properties of this oil in hybrid silicas were tested with disk diffusion experiments on bacterial cultures. The methyl–silica material with methyl/Si molar ratio 0.75 and load 7.5 % by mass of the encapsulated cinnamon essential oil presented adequate mechanical stability and maintained antibacterial properties for a prolonged period. This work has produced the first application of hybrid organic–inorganic silicas containing an essential oil for the design of antibacterial materials.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones Farmacéuticas (INIFAR)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic