Gravitação quadrática em (2 + 1)D com e sem termo topológico de Chern-Simons

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tópicos em teoria quântica de campos

Pós-graduação em Física - IFT

Investigating the effect of geographical distances and cultural proximity on the Hungarian wine trade

Wine is a very special product from an economic, cultural, and sociological point of view. Wine culture and wine trade play an important role in Hungary. The effect of cultural and geographical proximity on international trade has already been proven in the international trade literature. The size of bilateral trade flows between any two countries can be approximated by the gravity theory of trade. The gravity model provides empirical evidence of the relationship between the size of the economies, the distances between them, and their trade. This paper seeks to analyse the effect of cultural and geographical proximity on Hungary’s bilateral wine trade between 2000 and 2012, employing the gravity equation. The analysis is based on data from the World Bank WITS, WDI, as well as CEPII, and WTO databases. I apply OLS, Random Effects, Poisson, Pseudo-Poisson-Maximum-Likelihood and Heckman two stage estimators to calculate the gravity regression. The results show that in the case of Hungary, cultural similarity and trade liberalisation have a positive impact, while geographical distance, landlockedness, and contiguity have a negative impact on Hungarian wine exports.

The Hilbert space of the Chern-Simons theory on a cylinder: a loop quantum gravity approach

As a laboratory for loop quantum gravity, we consider the canonical quantization of the three-dimensional Chern-Simons theory on a noncompact space with the topology of a cylinder. Working within the loop quantization formalism, we define at the quantum level the constraints appearing in the canonical approach and completely solve them, thus constructing a gauge and diffeomorphism invariant physical Hilbert space for the theory. This space turns out to be infinite dimensional, but separable.

Higher-derivative theory of (2+1)-dimensional gravity

Higher-derivative gravity in 2 + 1 dimensions is considered. The general solution of the linearized field equations in a three-dimensional version of the Teyssandier gauge is obtained, and from that the solution for a static pointlike source is found. The deflection of light rays is also analysed. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Higgsing M2 to D2 with gravity: N=6 chiral supergravity from topologically gauged ABJM theory

We present the higgsing of three-dimensional N = 6 superconformal ABJM type theories coupled to conformal supergravity, so called topologically gauged ABJM theory, thus providing a gravitational extension of previous work on the relation between N M2 and N D2-branes. The resulting N = 6 supergravity theory appears at a chiral point similar to that of three-dimensional chiral gravity introduced recently by Li, Song and Strominger, but with the opposite sign for the Ricci scalar term in the lagrangian. We identify the supersymmetry in the broken phase as a particular linear combination of the supersymmetry and special conformal supersymmetry in the original topologically gauged ABJM theory. We also discuss the higgsing procedure in detail paying special attention to the role played by the U(1) factors in the original ABJM model and the U(1) introduced in the topological gauging.

Towards a Realization of the Condensed-Matter-Gravity Correspondence in String Theory via Consistent Abelian Truncation of the Aharony-Bergman-Jafferis-Maldacena Model

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Experimental results on gravity driven fully condensing flows in vertical tubes, their agreement with theory, and their differences with shear driven flows' boundary-condition sensitivities

This doctoral thesis presents the experimental results along with a suitable synthesis with computational/theoretical results towards development of a reliable heat transfer correlation for a specific annular condensation flow regime inside a vertical tube. For fully condensing flows of pure vapor (FC-72) inside a vertical cylindrical tube of 6.6 mm diameter and 0.7 m length, the experimental measurements are shown to yield values of average heat transfer co-efficient, and approximate length of full condensation. The experimental conditions cover: mass flux G over a range of 2.9 kg/m2-s ≤ G ≤ 87.7 kg/m2-s, temperature difference ∆T (saturation temperature at the inlet pressure minus the mean condensing surface temperature) of 5 ºC to 45 ºC, and cases for which the length of full condensation xFC is in the range of 0 < xFC < 0.7 m. The range of flow conditions over which there is good agreement (within 15%) with the theory and its modeling assumptions has been identified. Additionally, the ranges of flow conditions for which there are significant discrepancies (between 15 -30% and greater than 30%) with theory have also been identified. The paper also refers to a brief set of key experimental results with regard to sensitivity of the flow to time-varying or quasi-steady (i.e. steady in the mean) impositions of pressure at both the inlet and the outlet. The experimental results support the updated theoretical/computational results that gravity dominated condensing flows do not allow such elliptic impositions.

Field theory in superfluid 3He: What are the lessons for particle physics, gravity, and high-temperature superconductivity?

There are several classes of homogeneous Fermi systems that are characterized by the topology of the energy spectrum of fermionic quasiparticles: (i) gapless systems with a Fermi surface, (ii) systems with a gap in their spectrum, (iii) gapless systems with topologically stable point nodes (Fermi points), and (iv) gapless systems with topologically unstable lines of nodes (Fermi lines). Superfluid 3He-A and electroweak vacuum belong to the universality class 3. The fermionic quasiparticles (particles) in this class are chiral: they are left-handed or right-handed. The collective bosonic modes of systems of class 3 are the effective gauge and gravitational fields. The great advantage of superfluid 3He-A is that we can perform experiments by using this condensed matter and thereby simulate many phenomena in high energy physics, including axial anomaly, baryoproduction, and magnetogenesis. 3He-A textures induce a nontrivial effective metrics of the space, where the free quasiparticles move along geodesics. With 3He-A one can simulate event horizons, Hawking radiation, rotating vacuum, etc. High-temperature superconductors are believed to belong to class 4. They have gapless fermionic quasiparticles with a “relativistic” spectrum close to gap nodes, which allows application of ideas developed for superfluid 3He-A.

The distance of the sun from the earth determined by the theory of gravity ...

Supplement to his Tracts physical and mathematical.

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.