The Minimal Unitary Representation of E_8(8)

We give a new construction of the minimal unitary representation of the exceptional group E_8(8) on a Hilbert space of complex functions in 29 variables. Due to their manifest covariance with respect to the E_7(7) subgroup of E_8(8) our formulas are simpler than previous realizations, and thus well suited for applications in superstring and M theory.Comment: 24 pages, 1 figure, version to be published in ATM

BPS black holes, quantum attractor flows and automorphic forms

We propose a program for counting microstates of four-dimensional BPS black holes in N >= 2 supergravities with symmetric-space valued scalars by exploiting the symmetries of timelike reduction to three dimensions. Inspired by the equivalence between the four dimensional attractor flow and geodesic flow on the three-dimensional scalar manifold, we radially quantize stationary, spherically symmetric BPS geometries. Connections between the topological string amplitude, attractor wave function, the Ooguri-Strominger-Vafa conjecture and the theory of automorphic forms suggest that black hole degeneracies are counted by Fourier coefficients of modular forms for the three-dimensional U-duality group, associated to special "unipotent" representations which appear in the supersymmetric Hilbert space of the quantum attractor flow.Comment: 9 pages, revtex; v2: references added and typos correcte

Conformal and Quasiconformal Realizations of Exceptional Lie Groups

We present a nonlinear realization of E_8 on a space of 57 dimensions, which is quasiconformal in the sense that it leaves invariant a suitably defined ``light cone'' in 57 dimensions. This realization, which is related to the Freudenthal triple system associated with the unique exceptional Jordan algebra over the split octonions, contains previous conformal realizations of the lower rank exceptional Lie groups on generalized space times, and in particular a conformal realization of E_7 on a 27 dimensional vector space which we exhibit explicitly. Possible applications of our results to supergravity and M-Theory are briefly mentioned.Comment: 21 pages, 1 figure. Revised version. Connection between SU(8) and SL(8,R) bases clarified; formulas corrected; references adde

Minimal unitary representation of SU(2,2) and its deformations as massless conformal fields and their supersymmetric extensions

We study the minimal unitary representation (minrep) of SO(4,2) over an Hilbert space of functions of three variables, obtained by quantizing its quasiconformal action on a five dimensional space. The minrep of SO(4,2), which coincides with the minrep of SU(2,2) similarly constructed, corresponds to a massless conformal scalar in four spacetime dimensions. There exists a one-parameter family of deformations of the minrep of SU(2,2). For positive (negative) integer values of the deformation parameter \zeta one obtains positive energy unitary irreducible representations corresponding to massless conformal fields transforming in (0,\zeta/2) ((-\zeta/2,0)) representation of the SL(2,C) subgroup. We construct the supersymmetric extensions of the minrep of SU(2,2) and its deformations to those of SU(2,2|N). The minimal unitary supermultiplet of SU(2,2|4), in the undeformed case, simply corresponds to the massless N=4 Yang-Mills supermultiplet in four dimensions. For each given non-zero integer value of \zeta, one obtains a unique supermultiplet of massless conformal fields of higher spin. For SU(2,2|4) these supermultiplets are simply the doubleton supermultiplets studied in arXiv:hep-th/9806042.Comment: Revised with an extended introduction and additional references. Typos corrected. 49 pages; Latex fil

EM BUSCA DOS PRINCÍPIOS DA GESTÃO DA QUALIDADE TOTAL EM SERVIÇOS DE PROJETO DE ARQUITETURA: DESTAQUES DA TURQUIA

Proposal: Architectural design companies increasingly recognize that time spent on management is not at the expense of their production and there are always better ways to organize business. Although architects have long placed a traditional emphasis on quality, quality management is still a new concept for the majority of architectural design companies, which have to organize relatively more complicated operations nowadays to meet their clients’ expectations. This study aims to understand how architectural design companies define quality and explores the extent to which Total Quality Management (TQM) principles like continual improvement, employee involvement, customer satisfaction and others can be pertinent in these companies. Adopting a qualitative research strategy, the authors interviewed with the owner-managers of 10 widely-recognized architectural design companies of different size in Istanbul. The results from the content analysis of semi-structured interview data suggest that i) TQM principles cannot be directly applied in architectural design companies without an appropriate translation; ii) special characteristics of design services are important to explain quality-related perceptions of owner-managers; iii) the owner-managers feel the pressure from the changing internal and external environmental conditions, however few of them adopt a systematic and documented approach to quality management. Architectural design offices which aim to establish a quality management system can benefit from this study to understand potential problem areas on their road.As empresas de projeto de arquitetura cada vez mais reconhecem que o tempo dedicado à gestão não onera a sua produção e que há sempre maneiras de organizar melhor as atividades empresariais. Embora arquitetos tenham colocado durante muito tempo uma ênfase tradicional na qualidade, a gestão da qualidade ainda é um conceito novo para a maioria das empresas de projeto de arquitetura, que, hoje em dia, têm de organizar operações relativamente mais complicadas para atender às expectativas de seus clientes. Este estudo visa compreender de que modo as empresas de projeto de arquitetura definem qualidade e exploram os limites nos quais os princípios da gestão da qualidade total (TQM), como melhoria contínua, envolvimento dos funcionários, satisfação do cliente e outros, podem ser pertinentes para essas empresas. Adotando uma estratégia de pesquisa qualitativa, os autores entrevistaram os proprietários-gerentes de 10 empresas de projeto de arquitetura amplamente reconhecidas, de diferentes tamanhos, em Istambul. Os resultados da análise de conteúdo dos dados de entrevistas semi-estruturadas sugerem que: i) os princípios do TQM não podem ser aplicados diretamente em empresas de projeto de arquitetura, sem uma tradução adequada; ii) as características especiais dos serviços de projeto são importantes para explicar as percepções de proprietários-gerentes relacionadas à qualidade; iii) os proprietários-gerentes sentem a pressão da mudança interna e externa das condições ambientais, porém poucos deles adotam uma abordagem sistemática e documentada para a gestão da qualidade. Empresas de projeto de arquitetura que têm como objetivo estabelecer um sistema de gestão da qualidade podem se beneficiar deste estudo para conhecer as áreas potencialmente problemáticas que encontrarão

AdS_5 x S^5 Untwisted

Noting that T-duality untwists S^5 to CP^2 x S^1, we construct the duality chain: n=4 super Yang-Mills --> Type IIB superstring on AdS_5 x S^5 --> Type IIA superstring on AdS_5 x CP^2 x S^1 --> M-theory on AdS_5 x CP^2 x T^2. This provides another example of supersymmetry without supersymmetry: on AdS_5 x CP^2 x S^1, Type IIA supergravity has SU(3) x U(1) x U(1) x U(1) and N=0 supersymmetry but Type IIA string theory has SO(6) and N=8. The missing superpartners are provided by stringy winding modes. We also discuss IIB compactifications to AdS_5 with N=4, N=2 and N=0.Comment: 37 pages, Latex, references added and discussion expande

Supersymmetric branes with (almost) arbitrary tensions

We present a supersymmetric version of the two-brane Randall-Sundrum scenario, with arbitrary brane tensions T_1 and T_2, subject to the bound |T_{1,2}| \leq \sqrt{-6\Lambda_5}, where \Lambda_5 < 0 is the bulk cosmological constant. Dimensional reduction gives N=1, D=4 supergravity, with cosmological constant \Lambda_4 in the range \half\Lambda_5 \leq \Lambda_4 \leq 0. The case with \Lambda_4 = 0 requires T_1 = -T_2 = \sqrt{-6\Lambda_5}. This work unifies and generalizes previous approaches to the supersymmetric Randall-Sundrum scenario. It also shows that the Randall-Sundrum fine-tuning is not a consequence of supersymmetry.Comment: 19pp; Published versio

Fake Supergravity and Domain Wall Stability

We review the generalized Witten-Nester spinor stability argument for flat domain wall solutions of gravitational theories. Neither the field theory nor the solution need be supersymmetric. Nor is the space-time dimension restricted. We develop the non-trivial extension required for AdS-sliced domain walls and apply this to show that the recently proposed "Janus" solution of Type IIB supergravity is stable non-perturbatively for a broad class of deformations. Generalizations of this solution to arbitrary dimension and a simple curious linear dilaton solution of Type IIB supergravity are byproducts of this work.Comment: 37 pages, 3 figures, v2: minor corrections, references and acknowledgments adde

Black Holes, Qubits and Octonions

We review the recently established relationships between black hole entropy in string theory and the quantum entanglement of qubits and qutrits in quantum information theory. The first example is provided by the measure of the tripartite entanglement of three qubits, known as the 3-tangle, and the entropy of the 8-charge STU black hole of N=2 supergravity, both of which are given by the [SL(2)]^3 invariant hyperdeterminant, a quantity first introduced by Cayley in 1845. There are further relationships between the attractor mechanism and local distillation protocols. At the microscopic level, the black holes are described by intersecting D3-branes whose wrapping around the six compact dimensions T^6 provides the string-theoretic interpretation of the charges and we associate the three-qubit basis vectors, |ABC> (A,B,C=0 or 1), with the corresponding 8 wrapping cycles. The black hole/qubit correspondence extends to the 56 charge N=8 black holes and the tripartite entanglement of seven qubits where the measure is provided by Cartan's E_7 supset [SL(2)]^7 invariant. The qubits are naturally described by the seven vertices ABCDEFG of the Fano plane, which provides the multiplication table of the seven imaginary octonions, reflecting the fact that E_7 has a natural structure of an O-graded algebra. This in turn provides a novel imaginary octonionic interpretation of the 56=7 x 8 charges of N=8: the 24=3 x 8 NS-NS charges correspond to the three imaginary quaternions and the 32=4 x 8 R-R to the four complementary imaginary octonions. N=8 black holes (or black strings) in five dimensions are also related to the bipartite entanglement of three qutrits (3-state systems), where the analogous measure is Cartan's E_6 supset [SL(3)]^3 invariant.Comment: Version to appear in Physics Reports, including previously omitted new results on small STU black hole charge orbits and expanded bibliography. 145 pages, 15 figures, 41 table