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| 2. |
- Bao, Ling, 1980, et al.
(författare)
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A Note on Topological M5-branes and String-Fivebrane Duality
- 2006
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We derive the stability conditions for the M5-brane in topological M-theory using kappa-symmetry. The non-linearly self-dual 3-form on the world-volume is necessarily non-vanishing, as is the case also for the 2-form field strengths on coisotropic branes in topological string theory. It is demonstrated that the self-duality is consistent with the stability conditions, which are solved locally in terms of a tensor in the representation 6 of SU(3) in G_2. The double dimensional reduction of the M5-brane is the D4-brane, and its direct reduction is an NS5-brane. We show that the equation of motion for the 3-form on the NS5-brane wrapping a Calabi-Yau space is exactly the Kodaira-Spencer equation, providing support for a string-fivebrane duality in topological string theory.
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| 3. |
- Bengtsson, Ingemar, et al.
(författare)
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Covariant superstrings do not admit covariant gauge fixing
- 1984
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The covariant action for superstrings is analysed by means of the Diracmethod, and the light front action is derived. The action gives riseto second class constraints which cannot be solved for in a covariant way. Covariant gauge fixing, in any conventional sense, cannot be applied, which leaves the question of covariant quantisationof the superstrings open. A similar statement holds for a masslesssupersymmetric point-particle.
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| 4. |
- Bengtsson, Ingemar, et al.
(författare)
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Light cone actions for gravity and higher spins: some further results
- 1983
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- It has been suggested that field theories for arbitrary spin can be defined,using the light front formulation of dynamics. The higher order termsin the actions are discussed in this paper. We show that the gravity actioncan be written without ``time''-derivatives in the interaction termsin a way which appears generalisable to higher spin. Some problems forhigher spins are identified and briefly discussed.
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| 5. |
- 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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| 6. |
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| 7. |
- Cederwall, Martin, 1961
(författare)
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An off-shell superspace reformulation of D=4, N=4 super-Yang–Mills theory
- 2017
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- D = 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.
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| 8. |
- Cederwall, Martin, 1961
(författare)
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Bidivision algebra spinors in D=10 Minkowski geometry
- 1991
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Some geometrical properties of spinors in ten-dimensional Minkowski spaceare analysed, and are demonstrated to generalise the concept ofpure spinors to bi-division algebra spinors. In a unified treatment,they are shown to transform under orthogonal extensions ofthe algebra of space rotations and to be subjected to certainpurity constraints.
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| 9. |
- Cederwall, Martin, 1961, et al.
(författare)
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E8 geometry
- 2015
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We investigate exceptional generalised diffeomorphisms based on E_8(8) in a geometric setting. The transformations include gauge transformations for the dual gravity field. The surprising key result, which allows for a development of a tensor formalism, is that it is possible to define field-dependent transformations containing connection, which are covariant. We solve for the spin connection and construct a curvature tensor. A geometry for the Ehlers symmetry SL(n+1) is sketched. Some related issues are discussed.
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| 10. |
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