1. |
- Bertolini, Matteo, et al.
(författare)
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BPS three-brane solution on smooth ALE manifolds with flux
- 2002
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Ingår i: Fortsch. Phys.. ; 50, s. 802-
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Tidskriftsartikel (refereegranskat)abstract
- In the present talk I review the construction of a new supersymmetric 3-brane solution of type IIB supergravity on an ALE transverse space in presence of a non trivial flux of the complex 2-form across the ALE cycles. After introducing the ansatz for the solution I will show how the supergravity field equations reduce to a differential equation of Heun type in the non-conformal warp factor H of the metric. Although our analysis is worked out purely at a macroscopic level comments will be made on the general features of the (non-conformal) gauge theory dual to this solution
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2. |
- Bertolini, Matteo, et al.
(författare)
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Supersymmetric 3-branes on smooth ALE manifolds with flux
- 2001
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Ingår i: Nuclear Physics. ; B:617, s. 3-
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Tidskriftsartikel (refereegranskat)abstract
- We construct a new family of classical BPS solutions of type IIB supergravity describing 3-branes transverse to a 6-dimensional space with topology R^2*ALE. They are characterized by a non-trivial flux of the supergravity 2-forms through the homology 2-cycles of a generic smooth ALE manifold. Our solutions have two Killing spinors and thus preserve N=2 supersymmetry. They are expressed in terms of a quasi harmonic function H (the ``warp factor''), whose properties we study in the case of the simplest ALE, namely the Eguchi-Hanson manifold. The equation for H is identified as an instance of the confluent Heun equation. We write explicit power series solutions and solve the recurrence relation for the coefficients, discussing also the relevant asymptotic expansions. While, as in all such N=2 solutions, supergravity breaks down near the brane, the smoothing out of the vacuum geometry has the effect that the warp factor is regular in a region near the cycle. We interpret the behavior of the warp factor as describing a three-brane charge ``smeared'' over the cycle and consider the asymptotic form of the geometry in that region, showing that conformal invariance is broken even when the complex type IIB 3-form field strength is assumed to vanish. We conclude with a discussion of the basic features of the gauge theory dual.
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3. |
- Campos, Vanicson, 1972, et al.
(författare)
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The non-Abelian self dual string on the light cone
- 2000
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Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 0012, s. 11-
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Tidskriftsartikel (refereegranskat)abstract
- We construct the scalar profile for the non-abelian self dual string connecting two M5-branes compactified on a light-like circle. The construction is based on a conjectured modified version of Nahm's equations describing a D2-brane, with a magnetic field on it, suspended between two D4-branes. Turning on a constant magnetic field on the D2-brane corresponds to a boost in the eleventh direction. In the limit of infinite boost the D4-branes correspond to light-like compactified M5-branes. The solution for the scalar profile of the brane remains finite in this limit and displays all the correct expected features such as smooth interpolation between the unbroken and broken phase with the correct value for the Higgs field at infinity.
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4. |
- Cederwall, Martin, 1961, et al.
(författare)
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An introduction to analytical mechanics
- 2009
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- The present edition of this compendium is intended to be a complement to the textbook “Engineering Mechanics” by J.L. Meriam and L.G. Kraige (MK) for the course ”Mekanik F del 2” given in the first year of the Engineering physics (Teknisk fysik) programme at Chalmers University of Technology, Gothenburg. Apart from what is contained in MK, this course also encompasses an elementary understanding of analytical mechanics, especially the Lagrangian formulation. In order not to be too narrow, this text contains not only what is taught in the course, but tries to give a somewhat more general overview of the subject of analytical mechanics. The intention is that an interested student should be able to read additional material that may be useful in more advanced courses or simply interesting by itself. The chapter on the Hamiltonian formulation is strongly recommended for the student who wants a deeper theoretical understanding of the sub ject and is very relevant for the connection between classical mechanics (”classical” here denoting both Newton’s and Einstein’s theories) and quantum mechanics. The mathematical rigour is kept at a minimum, hopefully for the benefit of physical understanding and clarity. Notation is not always consistent with MK; in the cases it differs our notation mostly conforms with generally accepted conventions. The text is organised as follows: In Chapter 1 a background is given. Chapters 2, 3 and 4 contain the general setup needed for the Lagrangian formalism. In Chapter 5 Lagrange’s equation are derived and Chapter 6 gives their interpretation in terms of an action. Chapters 7 and 8 contain further developments of analytical mechanics, namely the Hamiltonian formulation and a Lagrangian treatment of constrained systems. Exercises are given at the end of each chapter. Finally, a translation table from English to Swedish of some terms used is found. Many of the exercise problems are borrowed from material by Ture Eriksson, Arne Kihlberg and Göran Niklasson. The selection of exercises has been focused on Chapter 5, which is of greatest use for practical applications.
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5. |
- Cederwall, Martin, 1961, et al.
(författare)
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Low energy dynamics of monopoles in N=2 SYM with matter
- 1995
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Ingår i: Mod.Phys.Lett. A11 (1996) 367.
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Tidskriftsartikel (refereegranskat)abstract
- We derive, for N=2 super-Yang-Mills with gauge group SU(2) and massless matter, the supersymmetric quantum mechanical models describing the time evolution of multi-monopole configurations in the low energy approximation. This is a first step towards identifying the solitonic states mapped to fundamental excitations by duality in the model with four hypermultiplets in the fundamental representation.
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6. |
- Edgren, Ludde, 1976, et al.
(författare)
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Infinite spin particles
- 2005
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Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; :5, s. 002 (artno)-
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Tidskriftsartikel (refereegranskat)abstract
- We show that Wigner's infinite spin particle classically is described by a reparametrization invariant higher order geometrical lagrangian. The model exhibits unconventional features like tachyonic behaviour and momenta proportional to light-like accelerations. A simple higher order superversion for half-odd integer particles is also derived. Interactions with external vector fields and curved spacetimes are analyzed with negative results except for (anti) de Sitter spacetimes. We quantize the free theories covariantly and show that the resulting wave functions are fields containing arbitrary large spins. Closely related infinite spin particle models are also analyzed.
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7. |
- Ferretti, Gabriele, 1963, et al.
(författare)
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D-brane probes on G(2) orbifolds
- 2002
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Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 03, s. 04-
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Tidskriftsartikel (refereegranskat)abstract
- We consider type-IIB string theory on a seven dimensional orbifold with holonomy in G2. The motivation is to use D1-branes as probes of the geometry. The low energy theory on the D1-brane is a sigma-model with two real supercharges (N = (1,1) in two dimensional language). We study in detail the closed and open string sectors and propose a coupling of the twisted fields to the brane that modifies the vacuum moduli space so that the singularity at the origin is removed. Instead of coming from D-terms, which are not present here, the modification comes from a ``twisted'' mass term for the seven scalar multiplets on the brane. The proposed mechanism involves a generalization of the moment map.
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