Type IIA/M-theory Moduli fixing in a Class of Orientifold Models

We present the study of type II A flux vacua and their M-theory duals for compactification on a class of Calabi-Yau orientifolds. The Kaehler potential is derived from toroidal compactifications and the superpotential contains a contribution from non-Abelian gauge degrees of freedoms. We obtain complete stabilisation of the moduli. We found one supersymmetric minimum and several non supersymmetric ones. Consistency of the analysis constrains the parameters of the models in a finite region containing a finite, although very large, number of flux vacua. From the M-theory side, we found some differences in the distributions of the physical quantities with respect to the M-theory ensemble studied by Acharya et al. In particular, it is easier to find small supersymmetry breaking scale.Comment: 37 pages, 4 figures, LaTeX. Extended one Section, added reference

De Sitter from T-branes

Hidden sector D7-branes with non-zero gauge flux are a generic feature of type IIB compactifications. A non-vanishing Fayet-Iliopoulos term induced by non-zero gauge flux leads to a T-brane configuration. Expanding the D7-brane action around this T-brane background in the presence of three-form supersymmetry breaking fluxes, we obtain a positive definite contribution to the moduli scalar potential which can be used as an uplifting source for de Sitter vacua. In this way we provide a higher-dimensional understanding of known 4D mechanisms of de Sitter uplifting based on hidden sector F-terms which are non-zero because of D-term stabilisation.Comment: 23 pages, 2 figure

Moduli Stabilisation with Nilpotent Goldstino: Vacuum Structure and SUSY Breaking

We study the effective field theory of KKLT and LVS moduli stabilisation scenarios coupled to an anti-D3-brane at the tip of a warped throat. We describe the presence of the anti-brane in terms of a nilpotent goldstino superfield in a supersymmetric effective field theory. The introduction of this superfield produces a term that can lead to a de Sitter minimum. We fix the Kaehler moduli dependence of the nilpotent field couplings by matching this term with the anti-D3-brane uplifting contribution. The main result of this paper is the computation, within this EFT, of the soft supersymmetry breaking terms in both KKLT and LVS for matter living on D3-brane (leaving the D7-brane analysis to an appendix). A handful of distinct phenomenological scenarios emerge that could have low energy implications, most of them having a split spectrum of soft masses. Some cosmological and phenomenological properties of these models are discussed. We also check that the attraction between the D3-brane and the anti-D3-brane does not affect the leading contribution to the soft masses and does not destabilise the system.Comment: 26+14 pages, 1 figure; references and clarifications added, typos fixe

T-branes through 3d mirror symmetry

T-branes are exotic bound states of D-branes, characterized by mutually non-commuting vacuum expectation values for the worldvolume scalars. The M/F-theory geometry lifting D6/D7-brane configurations is blind to the T-brane data. In this paper, we make this data manifest, by probing the geometry with an M2-brane. We find that the effect of a T-brane is to deform the membrane worldvolume superpotential with monopole operators, which partially break the three-dimensional flavor symmetry, and reduce supersymmetry from N=4 to N=2. Our main tool is 3d mirror symmetry. Through this language, a very concrete framework is developed for understanding T-branes in M-theory. This leads us to uncover a new class of N=2 quiver gauge theories, whose Higgs branches mimic those of membranes at ADE singularities, but whose Coulomb branches differ from their N=4 counterparts.Comment: 36 page

Possibilidades de acumulações de alguns benefícios concedidos pelo Regime Geral da Previdência Social

Benefícios são valores pagos em dinheiro aos segurados e dependentes. O presente artigo tem por objetivo analisar quais são os principais benefícios concedidos pela Previdência Social e quais podem ser acumulados. Trata-se de pesquisa qualitativa, realizada por meio de método dedutivo e de procedimento técnico bibliográfico e documental. Dessa forma, as reflexões partem do conceito e função de benefício para chegar até os diversos benefícios existentes. Em seguida, faz um estudo de quais são os principais benefícios concedidos pelo Regime Geral de Previdência Social e quais podem ser acumulados. Nesse sentido, conclui que os principais benefícios concedidos pela Previdência Social são: Aposentadoria por idade; Aposentadoria por tempo de serviço; Aposentadoria por tempo de contribuição; Aposentadoria especial; Aposentadoria por invalidez; Auxílio-doença; Auxílio-acidente; Pensão por morte; Auxílio-reclusão; Salário-maternidade; Salário-família; Abono anual e Benefício de Prestação Continuada ao Idoso e ao Deficiente – LOAS e que de acordo com a legislação em vigor, diversos benefícios não são acumuláveis, sendo que alguns até poderão se acumular, desde que atendidos os requisitos legais.Benefits are paid in cash to insured persons and their dependants. This article aims to analyze what are the main benefits granted by Social Security and which can be accumulated. This is qualitative research, conducted through the deductive method and bibliographic and documentary technical procedure. In this way, the reflections from the concept and function of benefit to reach the various existing benefits. Then, make a study of what are the main benefits granted by the General Social Security Scheme and which can be accumulated. Accordingly, concludes that the main benefits granted by Social Security: retirement age; Retirement for length of service; Retirement contribution time; Special retirement; Retirement due to disability; Sickness; Aid-accident; Death benefits; Aid-seclusion; Maternity pay; Family salary; Annual allowance and Benefit to provide the elderly and the Disabled Continued - LOAS and that according to the legislation in force, several benefits are not cumulative, and some, to be able to accumulate since they met legal requirements

Phenomenology from the Landscape of String Vacua

This article is the author's PhD thesis. After a review of string vacua obtained through compactification (with and wothout fluxes), it presents and describes various aspects of the Landscape of string vacua. At first it gives an introduction and an overview of the statistical study of the set of four dimensional string vacua, giving the detailed study of one corner of this set (G2-holonomy compactifications of M-theory). Then it presents the ten dimensional approach to string vacua, concentrating on the ten dimensional description of the Type IIA flux vacua. Finally it gives two examples of models having some interesting and characteristic phenomenological features, and that belong to two different corners of the Landscape: warped compactifications of Type IIB String Theory and M-theory compactifications on G2-holonomy manifolds.Comment: 170 pages; Ph.D. thesis (Advisor: Bobby S. Acharya); added reference

N=2 Heterotic-Type II duality and bundle moduli

Heterotic string compactifications on a $K3$ surface $\mathfrak{S}$ depend on a choice of hyperk\"ahler metric, anti-self-dual gauge connection and Kalb-Ramond flux, parametrized by hypermultiplet scalars. The metric on hypermultiplet moduli space is in principle computable within the $(0,2)$ superconformal field theory on the heterotic string worldsheet, although little is known about it in practice. Using duality with type II strings compactified on a Calabi-Yau threefold, we predict the form of the quaternion-K\"ahler metric on hypermultiplet moduli space when $\mathfrak{S}$ is elliptically fibered, in the limit of a large fiber and even larger base. The result is in general agreement with expectations from Kaluza-Klein reduction, in particular the metric has a two-stage fibration structure, where the $B$-field moduli are fibered over bundle and metric moduli, while bundle moduli are themselves fibered over metric moduli. A more precise match must await a detailed analysis of $R^2$-corrected ten-dimensional supergravity.Comment: 20 page

G 4 flux, algebraic cycles and complex structure moduli stabilization

We construct G4 fluxes that stabilize all of the 426 complex structure moduli of the sextic Calabi-Yau fourfold at the Fermat point. Studying flux stabilization usually requires solving Picard-Fuchs equations, which becomes unfeasible for models with many moduli. Here, we instead start by considering a specific point in the complex structure moduli space, and look for a flux that fixes us there. We show how to construct such fluxes by using algebraic cycles and analyze flat directions. This is discussed in detail for the sextic Calabi-Yau fourfold at the Fermat point, and we observe that there appears to be tension between M2-tadpole cancellation and the requirement of stabilizing all moduli. Finally, we apply our results to show that even though symmetric fluxes allow to automatically solve several F-term equations, they typically lead to flat directions