#### Filter Results:

- Full text PDF available (86)

#### Publication Year

1971

2017

- This year (4)
- Last 5 years (12)
- Last 10 years (41)

#### Publication Type

#### Co-author

#### Journals and Conferences

#### Key Phrases

Learn More

- Ulf Lindström, Ruben Minasian, Alessandro Tomasiello, Maxim Zabzine
- 2004

We find a worldsheet realization of generalized complex geometry, a notion introduced recently by Hitchin which interpolates between complex and symplectic manifolds. The two–dimensional model we construct is a supersymmetric relative of the Poisson sigma model used in context of deformation quantization.

- Ulf Lindström, Martin Roček, Rikard von Unge, Maxim Zabzine
- 2005

We solve the long standing problem of finding an off-shell supersymmetric formulation for a general N = (2, 2) nonlinear two dimensional sigma model. Geometrically the problem is equivalent to proving the existence of special coordinates; these correspond to particular superfields that allow for a superspace description. We construct and explain the… (More)

- Ulf Lindström
- 2002

On a historical note, we first describe the early superspace construction of counterterms in supergravity and then move on to a brief discussion of selected areas in string theory where higher order supergravity invariants enter the effective theories. Motivated by this description we argue that it is important to understand p-brane actions with κ-invariant… (More)

- Ferran Rey, Martin Roček, Simon Wiles, Ulf Lindström, R . von Unge
- 1997

Manifestly N = 2 supersymmetric Feynman rules are found for different off-shell realizations of the massless hypermultiplet in projective superspace. When we reduce the Feynman rules to an N = 1 superspace we obtain the correct component propagators. The Feynman rules are shown to be compatible with a “duality” that acts only on the auxiliary fields, as… (More)

- S . M . Kuzenko, Ulf Lindström, Martin Roček, G . Tartaglino - Mazzucchelli
- 2008

This paper presents a projective superspace formulation for 4D N = 2 mattercoupled supergravity. We first describe a variant superspace realization for the N = 2 Weyl multiplet. It differs from that proposed by Howe in 1982 by the choice of the structure group ( SO(3, 1)×SU(2) versus SO(3, 1)×U(2) ) , which implies that the super-Weyl transformations are… (More)

- Ulf Lindström, Martin Roček, Rikard von Unge, Maxim Zabzine
- 2004

Generalized complex geometry is a new mathematical framework that is useful for describing the target space of N = (2, 2) nonlinear sigma-models. The most direct relation is obtained at the N = (1, 1) level when the sigma model is formulated with an additional auxiliary spinorial field. We revive a formulation in terms of N = (2, 2) semi-(anti)chiral… (More)

The Green-Schwarz action for an open superstring with additional boundary fermions, representing Chan-Paton factors, is studied at the classical level. The boundary geometry is described by a bundle M̂ , with fermionic fibres, over the super worldvolume M of a D-brane together with a map from M̂ into the N = 2,D = 10 target superspace M . This geometry is… (More)

- Ulf Lindström, Sofia Exarchou, +7 authors Lth Jacobsson
- Scandinavian journal of rheumatology
- 2015

OBJECTIVES
Epidemiological studies of spondyloarthritis (SpA), using ICD codes from the Swedish National Patient Register (NPR), offer unique possibilities but hinge upon an understanding of the validity of the codes. The aim of this study was to validate the ICD codes for ankylosing spondylitis (AS) and undifferentiated SpA (uSpA) in the NPR against the… (More)

- Andreas Bredthauer, Ulf Lindström, Jonas
- 2005

We study the conditions under which N = (1, 1) generalized sigma models support an extension to N = (2, 2). The enhanced supersymmetry is related to the target space complex geometry. Concentrating on a simple situation, related to Poisson sigma models we develop a language that may help us analyze more complicated models in the future. In particular, we… (More)

- Cecilia Albertsson, Ulf Lindström, Maxim Zabzine
- 2001

We study an N = 1 two-dimensional non-linear sigma model with boundaries representing, e.g., a gauge fixed open string. We describe the full set of boundary conditions compatible with N = 1 superconformal symmetry. The problem is analysed in two different ways: by studying requirements for invariance of the action, and by studying the conserved… (More)