| 1. |
|
|
| 2. |
- Berman, David S., et al.
(författare)
-
Global aspects of double geometry
- 2014
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2014:9, s. article 66-19
-
Tidskriftsartikel (refereegranskat)abstract
- We consider the concept of a generalised manifold in the O(d,d) setting, i.e., in double geometry. The conjecture by Hohm and Zwiebach for the form of finite generalised diffeomorphisms is shown to hold. Transition functions on overlaps are defined. Triple overlaps are trivial concerning their action on coordinates, but non-trivial on fields, including the generalised metric. A generalised manifold is an ordinary manifold, but the generalised metric on the manifold carries a gerbe structure. We show how the abelian behaviour of the gerbe is embedded in the non-abelian T-duality group. We also comment on possibilities and difficulties in the U-duality setting.
|
|
| 3. |
- Berman, David S., et al.
(författare)
-
The gauge structure of generalised diffeomorphisms
- 2013
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 1301:1, s. 64-
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate the generalised diffeomorphisms in M-theory, which are gauge transformations unifying diffeomorphisms and tensor gauge transformations. After giving an En(n)-covariant description of the gauge transformations and their commutators, we show that the gauge algebra is infinitely reducible, i.e., the tower of ghosts for ghosts is infinite. The Jacobiator of generalised diffeomorphisms gives such a reducibility transformation. We give a concrete description of the ghost structure, and demonstrate that the infinite sums give the correct (regularised) number of degrees of freedom. The ghost towers belong to the sequences of rep- resentations previously observed appearing in tensor hierarchies and Borcherds algebras. All calculations rely on the section condition, which we reformulate as a linear condition on the cotangent directions. The analysis holds for n
|
|
| 4. |
- Cederwall, Martin, 1961
(författare)
-
D=11 supergravity with manifest supersymmetry
- 2010
-
Ingår i: Modern Physics Letters A. - 0217-7323. ; 25:38, s. 3201-3212
-
Tidskriftsartikel (refereegranskat)abstract
- The complete supersymmetric action for eleven-dimensional supergravity is presented. The action is polynomial in the scalar fermionic pure spinor superfield, and contains only a minor modification to the recently proposed three-point coupling.
|
|
| 5. |
- Cederwall, Martin, 1961, et al.
(författare)
-
D=3, N=8 conformal supergravity and the Dragon window
- 2011
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2011:9
-
Tidskriftsartikel (refereegranskat)abstract
- We give a superspace description of D=3, N=8 supergravity. The formulation is off-shell in the sense that the equations of motion are not implied by the superspace constraints (but an action principle is not given). The multiplet structure is unconventional, which we connect to the existence of a "Dragon window", that is modules occurring in the supercurvature but not in the supertorsion. According to Dragon's theorem this cannot happen above three dimensions. We clarify the relevance of this window for going on the conformal shell, and discuss some aspects of coupling to conformal matter.
|
|
| 6. |
|
|
| 7. |
- Cederwall, Martin, 1961, et al.
(författare)
-
Exceptional geometry and tensor fields
- 2013
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2013:7
-
Tidskriftsartikel (refereegranskat)abstract
- We present a tensor calculus for exceptional generalised geometry. Expressions for connections, torsion and curvature are given a unified formulation for different exceptional groups E_{n(n)}. We then consider "tensor gauge fields" coupled to the exceptional generalised gravity. Many of the properties of forms on manifolds are carried over to these fields.
|
|
| 8. |
- Cederwall, Martin, 1961
(författare)
-
From supergeometry to pure spinors
- 2010
-
Ingår i: Proceedings of 6th Mathematical Physics Meeting, Belgrade. - 9788682441304
-
Konferensbidrag (refereegranskat)abstract
- In this talk, we review how the superspace formulation of maximallysupersymmetric field theories (including supergravity) naturally leads tointroduction of pure spinors and pure spinor superfields, and why the formalismprovides off-shell formulations. This approach to pure spinor superfields thusstresses field-theoretic aspects rather than the first-quantised ones normallyused e.g. in superstring theory. We discuss how the BRST operator arises andthe principles behind constructions of actions, as well as the generalBatalin-Vilkovisky framework. D=11 supergravity and its recently constructedsupersymmetric action are taken as an example throughout the talk. This is thewritten version of a lecture given at the 6th Mathematical Physics Meeting,Belgrade, September 2010.
|
|
| 9. |
- Cederwall, Martin, 1961, et al.
(författare)
-
Loop amplitudes in maximal supergravity with manifest supersymmetry
- 2013
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2013:03
-
Tidskriftsartikel (refereegranskat)abstract
- We present a description for amplitude diagrams in maximal supergravities obtained by dimensional reduction from D = 11, derived from a field the- ory point of view using the pure spinor formalism. The advantages of this approach are the manifest supersymmetry present in the formalism, and the limited number of interaction terms in the action. Furthermore, we investi- gate the conditions set by this description in order for amplitudes in maximal supergravity to be finite in the ultraviolet limit. Typically, there is an upper limit to the dimension, set by the loop order, which for an arbitrary number of loops is no larger than two. In four dimensions, the non-renormalisation power of the formalism fails for the 7-loop contribution to the 4-point am- plitude, all of which is in clear agreement with previous work.
|
|
| 10. |
- Cederwall, Martin, 1961
(författare)
-
Non-gravitational exceptional supermultiplets
- 2013
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2013:7
-
Tidskriftsartikel (refereegranskat)abstract
- We examine non-gravitational minimal supermultiplets which are based on the tensor gauge fields appearing as matter fields in exceptional generalised geometry. When possible, off-shell multiplets are given. The fields in the multiplets describe non-gravitational parts of the internal dynamics of compactifications of M-theory. In flat backgrounds, they enjoy a global U-duality symmetry, but also provide multiplets with a possibility of coupling to a generalised exceptional geometry.
|
|
