Type I supergravity effective action from pure spinor formalism

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

Pure spinor vertex operators in Siegel gauge and loop amplitude regularization

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

Notes on the overall coefficient of the two-loop superstring amplitude using pure spinor

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

The cohomology of superspace, pure spinors and invariant integrals

The superform construction of supersymmetric invariants, which consists of integrating the top component of a closed superform over spacetime, is reviewed. The cohomological methods necessary for the analysis of closed superforms are discussed and some further theoretical developments presented. The method is applied to higher-order corrections in heterotic string theory up to alpha'(3). Some partial results on N = 2, d = 10 and N = 1, d = 11 are also given.

A new proposal for the picture changing operators in the minimal pure spinor formalism

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

Decoupling of unphysical states in the minimal pure spinor formalism II

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Simplifying and extending the AdS(5) x S-5 pure spinor formalism

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Explaining the pure spinor formalism for the superstring

After adding a pair of non-minimal fields and performing a similarity transformation, the BRST operator in the pure spinor formalism is expressed as a conventional-looking BRST operator involving the Virasoro constraint and (b, c) ghosts, together with 12 fermionic constraints. This BRST operator can be obtained by gauge-fixing the Green-Schwarz superstring where the 8 first-class and 8 second-class Green-Schwarz constraints are combined into 12 first-class constraints. Alternatively, the pure spinor BRST operator can be obtained from the RNS formalism by twisting the ten spin-half RNS fermions into five spin-one and five spin-zero fermions, and using the SO(10)/U(5) pure spinor variables to parameterize the different ways of twisting. GSO(-) vertex operators in the pure spinor formalism are constructed using spin fields and picture-changing operators in a manner analogous to Ramond vertex operators in the RNS formalism.

Langevin dynamics of the deconfinement transition for pure gauge theory

We investigate the effects of dissipation in the deconfinement transition for pure SU(2) and SU(3) gauge theories. Using an effective theory for the order parameter, we study its Langevin evolution numerically. Noise effects are included for the case of SU(2). We find that both dissipation and noise have dramatic effects on the spinodal decomposition of the order parameter and delay considerably its thermalization. For SU(3) the effects of dissipation are even larger than for SU(2).

Pure spinor partition function and the massive superstring spectrum

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

On semiclassical analysis of pure spinor superstring in an AdS(5) x S-5 background

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

Husserl on Geometry and Spatial Representation

Husserl left many unpublished drafts explaining (or trying to) his views on spatial representation and geometry, such as, particularly, those collected in the second part of Studien zur Arithmetik und Geometrie (Hua XXI), but no completely articulate work on the subject. In this paper, I put forward an interpretation of what those views might have been. Husserl, I claim, distinguished among different conceptions of space, the space of perception (constituted from sensorial data by intentionally motivated psychic functions), that of physical geometry (or idealized perceptual space), the space of the mathematical science of physical nature (in which science, not only raw perception has a word) and the abstract spaces of mathematics (free creations of the mathematical mind), each of them with its peculiar geometrical structure. Perceptual space is proto-Euclidean and the space of physical geometry Euclidean, but mathematical physics, Husserl allowed, may find it convenient to represent physical space with a non-Euclidean structure. Mathematical spaces, on their turn, can be endowed, he thinks, with any geometry mathematicians may find interesting. Many other related questions are addressed here, in particular those concerning the a priori or a posteriori character of the many geometric features of perceptual space (bearing in mind that there are at least two different notions of a priori in Husserl, which we may call the conceptual and the transcendental a priori). I conclude with an overview of Weyl's ideas on the matter, since his philosophical conceptions are often traceable back to his former master, Husserl.

Hydroxyapatite deposition study through polymeric process on commercially pure Ti surfaces modified by laser beam irradiation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pure-transvaginal natural orifice transluminal endoscopic surgery (NOTES) ovariohysterectomy in bitches: a preliminary feasibility study

Cirurgia endoscópica por orifícios naturais (NOTES) constitui um acesso cirúrgico relativamente novo para abordagem minimamente invasiva, a qual vem sendo amplamente estudada na medicina humana. Porém, poucos estudos envolvendo sua aplicação na prática cirúrgica de pequenos animais foram realizados até o momento. O objetivo do presente estudo foi avaliar a factibilidade da ovário-histerectomia transvaginal por NOTES pura em cadelas. Cinco cadelas foram avaliadas. A cavidade abdominal foi acessada por um trocarte de 11mm introduzido por uma incisão vaginal. Empregando-se um endoscópio rígido com canal de trabalho, os pedículos ovarianos foram coagulados e seccionados usando-se diatermia bipolar. O corno uterino foi tracionado para o interior do trocarte e exteriorizado juntamente com a cânula. O corpo e vasos uterinos foram coagulados ou ligados com sutura. O coto uterino foi reposicionado na cavidade abdominal e o pneumoperitônio, drenado. O procedimento foi realizado com sucesso em quatro das cinco cadelas. Na primeira tentativa, houve conversão para uma técnica de NOTES-híbrida, devido à quebra de uma pinça de coagulação. O tempo cirúrgico médio foi 52,1 (DP±11,5 minutos) para a técnica de NOTES pura. A OHE por NOTES pura é factível em cadelas, sem resultar em complicações maiores e proporcionando excelente recuperação pós-operatória.