1,950 research outputs found

    Coset Symmetries in Dimensionally Reduced Bosonic String Theory

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    We discuss the dimensional reduction of various effective actions, particularly that of the closed Bosonic string and pure gravity, to two and three dimensions. The result for the closed Bosonic string leads to coset symmetries which are in agreement with those recently predicted and argued to be present in a new unreduced formulation of this theory. We also show that part of the Geroch group appears in the unreduced duality symmetric formulation of gravity recently proposed. We conjecture that this formulation can be extended to a non-linear realisation based on a Kac-Moody algebra which we identify. We also briefly discuss the proposed action of Bosonic M-theory.Comment: Reference adde

    Dualisation of the General Scalar Coset in Supergravity Theories

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    The dualised formulation of the symmetric space sigma model is peformed for a general scalar coset G/K where G is a maximally non-compact group and K is it's maximal compact subgroup.By using the twisted self-duality condition the general form of the first-order equations are obtained.The results are applied to the example of SL(2,R)/SO(2) scalar manifold of the IIB supergravity.Comment: 22 page

    The group theory of oxidation II: Cosets of non-split groups

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    The oxidation program of hep-th/0210178 is extended to cover oxidation of 3-d sigma model theories on a coset G/H, with G non-compact (but not necessarily split), and H the maximal compact subgroup. We recover the matter content, the equations of motion and Bianchi identities from group lattice and Cartan involution. Satake diagrams provide an elegant tool for the computations, the maximal oxidation dimension, and group disintegration chains can be directly read off. We give a complete list of theories that can be recovered from oxidation of a 3 dimensional coset sigma model on G/H, where G is a simple non-compact group.Comment: 30 pages, LaTeX, 11 figures; v2. minor corrections, references adde

    Constitutive relations, off shell duality rotations and the hypergeometric form of Born-Infeld theory

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    We review equivalent formulations of nonlinear and higher derivatives theories of electromagnetism exhibiting electric-magnetic duality rotations symmetry. We study in particular on shell and off shell formulations of this symmetry, at the level of action functionals as well as of equations of motion. We prove the conjecture that the action functional leading to Born-Infeld nonlinear electromagnetism, that is duality rotation invariant off shell and that is known to be a root of an algebraic equation of fourth order, is a hypergeometric function.Comment: 20 pages. Contribution to the proceedings of the conference BUDS2013, Frascat

    Hidden symmetries in minimal five-dimensional supergravity

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    We study the hidden symmetries arising in the dimensional reduction of d=5, N=2 supergravity to three dimensions. Extending previous partial results for the bosonic part, we give a derivation that includes fermionic terms, shedding light on the appearance of the local hidden symmetry SO(4) in the reduction.Comment: 11 pages LaTeX, uses elsart and amssym

    Black Holes and U-Duality

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    We find the general charged rotating black hole solutions of the maximal supergravities in dimensions 4≀D≀94\le D\le 9 arising from toroidally compactified Type II string or M-theories. In each dimension, these are obtained by acting on a generating solution with classical duality symmetries. In D=4, D=5 and 6≀D≀96\le D \le 9 the generating solution is specified by the ADM mass, [D−1/2][{D-1}/2]-angular momentum components and five, three and two charges, respectively. We discuss the BPS-saturated (static) black holes and derive the U-duality invariant form of the area of the horizon. We also comment on the U-duality invariant form of the BPS mass formulae.Comment: Minor corrections. Version to appear in Nuclear Physics

    The group theory of oxidation

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    Dimensional reduction of (super-)gravity theories to 3 dimensions results in sigma models on coset spaces G/H, such as the E_8/SO(16) coset in the bosonic sector of 3 dimensional maximal supergravity. The reverse process, oxidation, is the reconstruction of a higher dimensional gravity theory from a coset sigma model. Using the group G as starting point, the higher dimensional models follow essentially from decomposition into subgroups. All equations of motion and Bianchi identities can be directly reconstructed from the group lattice, Kaluza-Klein modifications and Chern-Simons terms are encoded in the group structure. Manipulations of extended Dynkin diagrams encode matter content, and (string) dualities. The reflection symmetry of the ``magic triangle'' for E_n gravities, and approximate reflection symmetry of the older ``magic triangle'' of supergravities in 4 dimensions, are easily understood in this framework.Comment: 50 pages, LaTeX, 3 figures, 5 tables; v2. typo's fixed, references added, clarified derivation of sigma model equation of motion in appendix D; v3. small corrections, more reference

    A Comment on the Cosmological Constant Problem in Spontaneously Broken Supergravity

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    In spontaneously broken supergravity with non-flat potential the vanishing of the cosmological constant is usually associated with a non-trivial balancing of two opposite-sign contributions. We make the simple observation that, in an appropriately defined expansion of the superfield action in inverse powers of MPM_P, this tuning corresponds to the absence of two specific operators. It is then tempting to speculate what kind of non-standard symmetry or structural principle might underlie the observed extreme smallness of the corresponding coefficients in the real world. Independently of such speculations, the suggested expansion appears to be a particularly simple and convenient starting point for the effective field theory analysis of spontaneously broken supergravity models.Comment: 6 pages LaTe

    Kac-Moody Symmetries of IIB Supergravity

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    We formulate the bosonic sector of IIB supergravity as a non-linear realisation. We show that this non-linear realisation contains the Borel subalgebras of SL(11) and E7E_7 and argue that it can be enlarged so as to be based on the rank eleven Kac-Moody algebra E11E_{11}Comment: 12 pages, plain te