Non-Perturbative Methods in Quantum Field Theory and Quantum Gravity

This thesis considers non-perturbative methods in quantum field theory with applications to gravity and cosmology. In particular, there are chapters on black hole holography, inflationary model building, and the conformal bootstrap.

Perturbative and non perturbative effects in the Standard Model and orbifolded ADS/CFT based theories

We study some perturbative and nonperturbative effects in the framework of the Standard Model of particle physics. In particular we consider the time dependence of the Higgs vacuum expectation value given by the dynamics of the StandardModel and study the non-adiabatic production of both bosons and fermions, which is intrinsically non-perturbative. In theHartree approximation, we analyze the general expressions that describe the dissipative dynamics due to the backreaction of the produced particles. Then, we solve numerically some relevant cases for the Standard Model phenomenology in the regime of relatively small oscillations of the Higgs vacuum expectation value (vev). As perturbative effects, we consider the leading logarithmic resummation in small Bjorken x QCD, concentrating ourselves on the Nc dependence of the Green functions associated to reggeized gluons. Here the eigenvalues of the BKP kernel for states of more than three reggeized gluons are unknown in general, contrary to the large Nc limit (planar limit) case where the problem becomes integrable. In this contest we consider a 4-gluon kernel for a finite number of colors and define some simple toy models for the configuration space dynamics, which are directly solvable with group theoretical methods. In particular we study the depencence of the spectrum of thesemodelswith respect to the number of colors andmake comparisons with the planar limit case. In the final part we move on the study of theories beyond the Standard Model, considering models built on AdS5 S5/Γ orbifold compactifications of the type IIB superstring, where Γ is the abelian group Zn. We present an appealing three family N = 0 SUSY model with n = 7 for the order of the orbifolding group. This result in a modified Pati–Salam Model which reduced to the StandardModel after symmetry breaking and has interesting phenomenological consequences for LHC.

Physicality in the Information Age : a normative perspective on the patent eligibility of non-physical methods

There has been much conjecture of late as to whether the patentable subject matter standard contains a physicality requirement. The issue came to a head when the Federal Circuit introduced the machine-or-transformation test in In re Bilski and declared it to be the sole test for determining subject matter eligibility. Many commentators criticized the test, arguing that it is inconsistent with Supreme Court precedent and the need for the patent system to respond appropriately to all new and useful innovation in whatever form it arises. Those criticisms were vindicated when, on appeal, the Supreme Court in Bilski v. Kappos dispensed with any suggestion that the patentable subject matter test involves a physicality requirement. In this article, the issue is addressed from a normative perspective: it asks whether the patentable subject matter test should contain a physicality requirement. The conclusion reached is that it should not, because such a limitation is not an appropriate means of encouraging much of the valuable innovation we are likely to witness during the Information Age. It is contended that it is not only traditionally-recognized mechanical, chemical and industrial manufacturing processes that are patent eligible, but that patent eligibility extends to include non-machine implemented and non-physical methods that do not have any connection with a physical device and do not cause a physical transformation of matter. Concerns raised that there is a trend of overreaching commoditization or propertization, where the boundaries of patent law have been expanded too far, are unfounded since the strictures of novelty, nonobviousness and sufficiency of description will exclude undeserving subject matter from patentability. The argument made is that introducing a physicality requirement will have unintended adverse effects in various fields of technology, particularly those emerging technologies that are likely to have a profound social effect in the future.

World emissions and economic growth: Application of non-parametric methods

The Environmental Kuznets Curve (EKC) hypothesises an inverse U-shaped relationship between a measure of environmental pollution and per capita income levels. In this study, we apply non-parametric estimation of local polynomial regression (local quadratic fitting) to allow more flexibility in local estimation. This study uses a larger and globally representative sample of many local and global pollutants and natural resources including Biological Oxygen Demand (BOD) emission, CO2 emission, CO2 damage, energy use, energy depletion, mineral depletion, improved water source, PM10, particulate emission damage, forest area and net forest depletion. Copyright © 2009 Inderscience Enterprises Ltd.

Crystallization kinetics of SrBi2B2O7 glasses by non-isothermal methods

Transparent glasses of SrBi2B2O7 (SBBO) were fabricated via the conventional melt-quenching technique. The amorphous and the glassy nature of the as-quenched samples were, respectively, confirmed by X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC). The glass transition (T (g)) and the crystallization parameters [crystallization activation energy (E (cr)) and Avrami exponent (n)] were evaluated under non-isothermal conditions using DSC. There was a close agreement between the activation energies for the crystallization process determined by Augis and Bennet and Kissinger methods. The variation of local activation energy [E (c)(x)] that was determined by Ozawa method, decreased with the fraction of crystallization (x). The Avrami exponent (n(x)) increased with the increase in fraction of crystallization (x) suggesting that there was a change over in the crystallization process from the surface to the bulk.

Non-interferometric methods of phase estimation for application in optical tomography

We describe here two non-interferometric methods for the estimation of the phase of transmitted wavefronts through refracting objects. The phase of the wavefronts obtained is used to reconstruct either the refractive index distribution of the objects or their contours. Refraction corrected reconstructions are obtained by the application of an iterative loop incorporating digital ray tracing for forward propagation and a modified filtered back projection (FBP) for reconstruction. The FBP is modified to take into account non-straight path propagation of light through the object. When the iteration stagnates, the difference between the projection data and an estimate of it obtained by ray tracing through the final reconstruction is reconstructed using a diffraction tomography algorithm. The reconstruction so obtained, viewed as a correction term, is added to the estimate of the object from the loop to obtain an improved final refractive index reconstruction.

On the Selection of Non-Invasive Methods Based on Speech Analysis Oriented to Automatic Alzheimer Disease Diagnosis

The work presented here is part of a larger study to identify novel technologies and biomarkers for early Alzheimer disease (AD) detection and it focuses on evaluating the suitability of a new approach for early AD diagnosis by non-invasive methods. The purpose is to examine in a pilot study the potential of applying intelligent algorithms to speech features obtained from suspected patients in order to contribute to the improvement of diagnosis of AD and its degree of severity. In this sense, Artificial Neural Networks (ANN) have been used for the automatic classification of the two classes (AD and control subjects). Two human issues have been analyzed for feature selection: Spontaneous Speech and Emotional Response. Not only linear features but also non-linear ones, such as Fractal Dimension, have been explored. The approach is non invasive, low cost and without any side effects. Obtained experimental results were very satisfactory and promising for early diagnosis and classification of AD patients.

Non-invasive methods for identifying oocysts of Sarcocystis spp. from definitive hosts

Because the excreted sporocysts and/or oocysts of various species of Sarcocystis may not be discriminated morphologically, we sought to validate a diagnostic technique based on variation in the 18S rDNA sequence. Oocysts and/or sporocysts; from three taxa

Determination of the degradation kinetics of anthocyanins in a model juice system using isothermal and non-isothermal methods

The effect of temperature on the degradation of blackcurrant anthocyanins in a model juice system was determined over a temperature range of 4–140 °C. The thermal degradation of anthocyanins followed pseudo first-order kinetics. From 4–100 °C an isothermal method was used to determine the kinetic parameters. In order to mimic the temperature profile in retort systems, a non-isothermal method was applied to determine the kinetic parameters in the model juice over the temperature range 110–140 °C. The results from both isothermal and non-isothermal methods fit well together, indicating that the non-isothermal procedure is a reliable mathematical method to determine the kinetics of anthocyanin degradation. The reaction rate constant (k) increased from 0.16 (±0.01) × 10−3 to 9.954 (±0.004) h−1 at 4 and 140 °C, respectively. The temperature dependence of the rate of anthocyanin degradation was modelled by an extension of the Arrhenius equation, which showed a linear increase in the activation energy with temperature.

Non invasive methods for genetic analysis applied to ecological and behavioral studies in Latino-America

Documenting the presence and abundance of the neotropical mammals is the first step for understanding their population ecology, behavior and genetic dynamics in designing conservation plans. The combination of field research with molecular genetics techniques are new tools that provide valuable biological information avoiding the disturbance in the ecosystems, trying to minimize the human impact in the process to gather biological information. The objective of this paper is to review the available non invasive sampling techniques that have been used in Neotropical mammal studies to apply to determine the presence and abundance, population structure, sex ratio, taxonomic diagnostic using mitochondrial markers, and assessing genetic variability using nuclear markers. There are a wide range of non invasive sampling techniques used to determine the species identification that inhabit an area such as searching for tracks, feces, and carcasses. Other useful equipment is the camera traps that can generate an image bank that can be valuable to assess species presence and abundance by morphology. With recent advances in molecular biology, it is now possible to use the trace amounts of DNA in feces and amplify it to analyze the species diversity in an area, and the genetic variability at intraspecific level. This is particularly helpful in cases of sympatric and cryptic species in which morphology failed to diagnose the taxonomic status of several species of brocket deer of the genus Mazama.

Quantum vacuum in hot nuclear matter: A non-perturbative treatment

We derive the equation of state for hot nuclear matter using the Walecka model in a non-perturbative formalism. We include here the vacuum polarization effects arising from the nucleon and scalar mesons through a realignment of the vacuum. A ground state structure with baryon-antibaryon condensates yields the results obtained through the relativistic Hartree approximation of summing baryonic tadpole diagrams. Generalization of such a state to include the quantum effects for the scalar meson fields through the σ -meson condensates amounts to summing over a class of multiloop diagrams. The techniques of the thermofield dynamics method are used for the finite-temperature and finite-density calculations. The in-medium nucleon and sigma meson masses are also calculated in a self-consistent manner. We examine the liquid-gas phase transition at low temperatures (≈ 20 MeV), as well as apply the formalism to high temperatures to examine a possible chiral symmetry restoration phase transition.

Non-perturbative fixed points and renormalization group improved effective potential

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)