Super Poisson-Lie symmetry of the GL(1|1) WZNW model and worldsheet boundary conditions

We show that the WZNW model on the Lie supergroup GL(1|1) has super Poisson-Lie symmetry with the dual Lie supergroup B + A + A1;1|.i. Then, we discuss about D-branes and worldsheet boundary conditions on supermanifolds, in general, and obtain the algebraic relations on the gluing supermatrix for the Lie supergroup case. Finally, using the supercanonical transformation description of the super Poisson-Lie T-duality transformation, we obtain formula for the description of the dual gluing supermatrix, then, we find the gluing supermatrix for the WZNW model on GL(1|1) and its dual model. We also discuss about different boundary conditions.Comment: 19 pages, two Refs. have adde

Fermionic Coset, Critical Level W^(2)_4-Algebra and Higher Spins

The fermionic coset is a limit of the pure spinor formulation of the AdS5xS5 sigma model as well as a limit of a nonlinear topological A-model, introduced by Berkovits. We study the latter, especially its symmetries, and map them to higher spin algebras. We show the following. The linear A-model possesses affine \AKMSA{pgl}{4}{4}_0 symmetry at critical level and its \AKMSA{psl}{4}{4}_0 current-current perturbation is the nonlinear model. We find that the perturbation preserves $\mathcal{W}^{(2)}_4$-algebra symmetry at critical level. There is a topological algebra associated to \AKMSA{pgl}{4}{4}_0 with the properties that the perturbation is BRST-exact. Further, the BRST-cohomology contains world-sheet supersymmetric symplectic fermions and the non-trivial generators of the $\mathcal{W}^{(2)}_4$-algebra. The Zhu functor maps the linear model to a higher spin theory. We analyze its \SLSA{psl}{4}{4} action and find finite dimensional short multiplets.Comment: 25 page

Replicate and generalize to make urban research coherent

Scientific approaches to urban research are a century in the making but have long remained tangled in debates and disagreements. Here, we reflect on how current enthusiasm for a scientific urbanism resurfaces old conflicts and suggest that a diverse set of arguments revolve around two concepts: replication and generalizability. We argue that addressing these challenges directly could play an important role in advancing empirical research. New empirical methods, including those coming from artificial intelligence, offer means of radically accelerating urban research, but also risk a revisiting of longstanding disagreements. Applying replication and generalizability as a conceptual bridge may be key to some of these new methods contributing to a more integrated and interdisciplinary urbanism. Beyond empirical urbanism, replication and generalizability may enable the development of a more integrated, systematic urban field by supporting the translation of methodologies, findings, and theories between disciplines. We conclude by cautioning that further work is needed to understand how replication and generalizability apply across the urban field (significant areas of which are not addressed in this paper) and by calling for authors to test the value of replication and generalizability in their areas of urban expertise

Harmonic Analysis and Free Field Realization of the Takiff Supergroup of GL(1|1)

Takiff superalgebras are a family of non semi-simple Lie superalgebras that are believed to give rise to a rich structure of indecomposable representations of associated conformal field theories. We consider the Takiff superalgebra of gl(1|1), especially we perform harmonic analysis for the corresponding supergroup. We find that every simple module appears as submodule of an infinite-dimensional indecomposable but reducible module. We lift our results to two free field realizations for the corresponding conformal field theory and construct some modules

Higher spin AdS_3 holography with extended supersymmetry

We propose a holographic duality between a higher spin AdS_3 gravity with so(p) extended supersymmetry and a large N limit of a 2-dimensional Grassmannian-like model with a specific critical level k=N and a non-diagonal modular invariant. As evidence, we show the match of one-loop partition functions. Moreover, we construct symmetry generators of the coset model for low spins which are dual to gauge fields in the supergravity. Further, we discuss a possible relation to superstring theory by noticing an N=3 supersymmetry of critical level model at finite k,N. In particular, we examine BPS states and marginal deformations. Inspired by the supergravity side, we also propose and test another large N CFT dual obtained as a Z_2 automorphism truncation of a similar coset model, but at a non-critical level.Comment: 44 pages, published versio

Yangian in the Twistor String

We study symmetries of the quantized open twistor string. In addition to global PSL(4|4) symmetry, we find non-local conserved currents. The associated non-local charges lead to Ward identities which show that these charges annihilate the string gluon tree amplitudes, and have the same form as symmetries of amplitudes in N=4 super conformal Yang Mills theory. We describe how states of the open twistor string form a realization of the PSL(4|4) Yangian superalgebra.Comment: 37 pages, 4 figure

Topological String on OSP(1|2)/U(1)

We propose an equivalence between topological string on OSP(1|2)/U(1) and \hat{c} \leq 1 superstring with N=1 world-sheet supersymmetry. We examine this by employing a free field representation of OSP(1|2) WZNW model and find an agreement on the spectrum. We also analyze this proposal at the level of scattering amplitudes by applying a map between correlation functions of OSP(1|2) WZNW model and those of N=1 Liouville theory.Comment: 25 pages, refereces adde

On the coset duals of extended higher spin theories

We study the holographic duality between the M x M matrix extension of Vasiliev higher spin theories on AdS3 and the large N limit of SU(N+M)/SU(N) x U(1) type cosets. We present a simplified proof for the agreement of the spectra and clarify the relation between this duality and the version in which the cosets are replaced by Kazama-Suzuki models of Grassmannian type.Comment: 27 pages, 1 tabl