280 research outputs found
World-volume fields and background coupling of branes
No full textthis paper, are by now fairly well understood. Although a fundamental microscopic formulation of the theory is still missing, the evidence is overwhelming that the different perturbative superstring theories, their low-energy supergravity theories and 11-dimensional supergravity are different manifestations of one underlying non-perturbative theory. In this talk, there is not much time to discuss the roles that the different elementary and solitonic objects have in the various duality transformations between different perturbative theories. We refer to ref. [1]. Some will be mentioned briefly, but the emphasis is put on the description of the dynamics of branes occurring in superstring theory/M-theory. 2. Charged branes The means to describe brane dynamics is to formulate actions, fulfilling certain requirements. In this section, some things will be said about the basic ingredients in these actions. The methods will later be refined. We let the dimensionality of the brane world-volume be p+1 and that of Martin Cederwall: "World-volume fields and background coupling of branes" : : : : : : : : : : : : : : : : 2 space-time D
Introduction ti Division Algebras, . . .
No full textA very basic introduction is given to the roles of division algebras and the related sphere algebras concerning the structure of space-time in the dimensionalities D = 3; 4; 6 and 10, with special emphasis on twistors transformations for lightlikeness conditions and Hopf maps, together with some outlook for particle and string theory. Talk presented at the Theoretical Physics Network Meeting at NORDITA, Copenhagen, September 1993 ? e-mail [email protected] M. Cederwall, "Introduction to Division Algebras, Sphere Algebras and Twistors" This introduction, given the condition that it should fit into a single lecture, will be quite schematical. Many mathematical and technical details will be left out, for the purpose of giving a more intuitive overview of the subject. The intention is that the listener/reader should get a starting point for more detailed or extensive study. There will be nothing said about supersymmetry, although its incorporation in the context of twistors is very ..
S 7 and. . .
No full textWe investigate the seven-sphere as a group-like manifold and its extension to a Kac-Moodylike algebra. Covariance properties and tensorial composition of spinors under S 7 are defined. The relation to Malcev algebras is established. The consequences for octonionic projective spaces are examined. Current algebras are formulated and their anomalies are derived, and shown to be unique (even regarding numerical coefficients) up to redefinitions of the currents. Nilpotency of the BRST operator is consistent with one particular expression in the class of (field-dependent) anomalies. A Sugawara construction is given. published in Commun.Math.Phys. 167 (1995) 373. ? e-mail [email protected] y e-mail [email protected] M. Cederwall and C.R. Preitschopf, "S 7 and c S 7 " 1. Preliminaries. This paper is devoted to an investigation of the seven-sphere as a manifold equipped with group-like multiplication, and to its extension to a Kac-Moody-like algebra. As is well known, the seven-..
An action for the super-5-brane in D=11 supergravity
No full text: An alternative path is taken for deriving an action for the supersymmetric 5brane in 11 dimensions. Selfduality does not follow from the action, but is consistent with the equations of motion for arbitrary supergravity backgrounds. The action involves a 2-form as well as a 5-form world-volume potential; inclusion of the latter makes the action, as well as the non-linear selfduality relation for the 3-form field strength, polynomial. The requirement of invariance under -transformations determines the form of the selfduality relation, as well as the action. The formulation is shown to be equivalent to earlier formulations of 5-brane dynamics. M. Cederwall, B.E.W. Nilsson, P. Sundell: "An action for the super-5-brane: : :" : : : : : : : : : : : : : : : 2 11-dimensional supergravity [1] is believed to be the low-energy effective theory for M-theory. Arising as a strong coupling limit of type IIA superstring theory [2], it is connected to the entire web of dualities relating different v..
Deformations in Closed String Theory --- Canonical Formulation and Regularization
No full text: We study deformations of closed string theory by primary fields of conformal weight (1; 1), using conformal techniques on the complex plane. A canonical surface integral formalism for computing commutators in a non-holomorphic theory is constructed, and explicit formulae for deformations of operators are given. We identify the unique regularization of the arising divergences that respects conformal invariance, and consider the corresponding parallel transport. The associated connection is metric compatible and carries no curvature. accepted for publication in Nucl.Phys. B. email addresses: [email protected] [email protected] [email protected] Cederwall, von Gussich, Sundell: Deformations in Closed String Theory : : : : : : : : : : : 2 1. Introduction and Summary Probably the most important theoretical problem concerning string theory is the lack of a "covariant" formulation. Despite the fact that closed string theory contains gravity as part of the infinite spectrum, the..
Goldstone tensor modes
No full textIn the context of brane solutions of supergravity, we discuss a general method to introduce collective modes of any spin by exploiting a particular way of breaking symmetries. The method is applied to the D3, M2 and M5 branes and we derive explicit expressions for how the zero-modes enter the target space fields, verify normalisability in the transverse directions and derive the corresponding field equations on the brane. In particular, the method provides a clear understanding of scalar, spinor, and rank r tensorial Goldstone modes, chiral as well as non-chiral, and how they arise from the gravity, Rarita-Schwinger, and rank r + 1 Kalb-Ramond tensor gauge fields, respectively. Some additional observations concerning the chiral tensor modes on the M5 brane are discussed. Adawi, Cederwall, Gran, Nilsson, Razaznejad: \Goldstone Tensor Modes ".............. 2 1
Superembeddings, Non-linear Supersymmetry and 5-branes
No full textWe examine general properties of superembeddings, i.e., embeddings of supermanifolds into supermanifolds. The connection between an embedding procedure and the method of non-linearly realised supersymmetry is clarified, and we demonstrate how the latter arises as a special case of the former. As an illustration, the super-5-brane in 7 dimensions, containing a self-dual 3-form world-volume field strength, is formulated in both languages, and provides an example of a model where the embedding condition does not suffice to put the theory on-shell. T. Adawi, M. Cederwall, U. Gran, M. Holm, B.E.W. Nilsson: "Superembeddings: : :" : : : : : : : : : : : : : 2 1. Introduction Our understanding of string theory at the non-perturbative level has gone through a dramatic improvement in recent years. Some of the key aspects of this development are connected to the central role played by solitonic solutions of the low energy field equations, i.e., various brane configurations that solve the field e..
An off-shell superspace reformulation of D=4, N=4 super-Yang–Mills theory
No full textD = 4, N = 4 super-Yang-Mills theory has an off-shell superspace formulation in terms of pure spinor superfields, which is directly inherited from the D = 10 theory. That superspace, in particular the choice of pure spinor variables, is less suitable for dealing with fields that are inherently 4-dimensional, such as the superfields based on the scalars, which are gauge-covariant, and traces of powers of scalars, which are gauge-invariant. We give a reformulation of D = 4, N = 4 super-Yang-Mills theory in N = 4 superspace, using inherently 4-dimensional pure spinors. All local degrees of freedom reside in a superfield based on the physical scalars. The formalism should be suited for calculations of correlators of traces of scalar superfields
Algebraic structures in exceptional geometry
No full textExceptional field theory (EFT) gives a geometric underpinning of the U-duality symmetries of M-theory. In this talk I give an overview of the surprisingly rich algebraic structures which naturally appear in the context of EFT. This includes Borcherds superalgebras, Cartan type superalgebras (tensor hierarchy algebras) and L∞ algebras. This is the written version of a talk based mainly on refs. [1-6], presented at ISQS25, Prague, June 2017, at QTS-10/LT-12, Varna, June 2017, at SQS 2017, Dubna, Aug. 2017, and at the 9th Mathematical Physics Meeting, Belgrade, Sept. 2017
Double supergeometry
No full textA geometry of superspace corresponding to double field theory is developed, with type II supergravity in D=10 as the main example. The formalism is based on an orthosymplectic extension OSp(d,d|2s) of the continuous T-duality group. Covariance under generalised super-diffeomorphisms is manifest. Ordinary superspace is obtained as a solution of the orthosymplectic section condition. A systematic study of curved superspace Bianchi identities is performed, and a relation to a double pure spinor superfield cohomology is established. A Ramond-Ramond superfield is constructed as an infinite-dimensional orthosymplectic spinor. Such objects in minimal orbits under the OSp supergroup ("pure spinors") define super-sections
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