Zobrazeno 1 - 10
of 120
pro vyhledávání: '"Danielsson, Ulf H."'
Autor:
Danielsson, Ulf H.
In this paper we propose a quantum version of the swampland conjecture. We argue that quantum instabilities of de Sitter space discovered using field theoretical methods, are directly related to the difficulties in finding stringy de Sitter vacua.
Externí odkaz:
http://arxiv.org/abs/1809.04512
Autor:
Danielsson, Ulf H., Van Riet, Thomas
We present a brief overview of attempts to construct de Sitter vacua in string theory and explain how the results of this 20-year endeavor could point to the fact that string theory harbors no de Sitter vacua at all. Making such a statement is often
Externí odkaz:
http://arxiv.org/abs/1804.01120
Autor:
Danielsson, Ulf H.
In this paper we suggest a new source of perturbative decay of the KPV-state, which might have consequences for the viability of the KKLT-construction. The results do not rely on any direct enhancement of the decay due to flux accumulating on the ant
Externí odkaz:
http://arxiv.org/abs/1502.01234
Autor:
Danielsson, Ulf H., Van Riet, Thomas
We elaborate on the decay of branes inside throat geometries that are supported by flux carrying charges opposite to the brane. Our main point is that such backgrounds necessarily have a local, possibly diverging, pile up of brane-charges dissolved i
Externí odkaz:
http://arxiv.org/abs/1410.8476
In the known examples of flux vacua with calibrated spacetime-filling sources (branes or orientifold planes), one can smear the source in order to perform a standard KK reduction and obtain a lower-dimensional supergravity description. Furthermore, i
Externí odkaz:
http://arxiv.org/abs/1311.6470
Publikováno v:
JHEP 1303:138,2013
The stabilisation of the dilaton and volume in tree-level flux compactifications leads to model independent and thus very powerful existence and stability criteria for dS solutions. In this paper we show that the sizes of cycles wrapped by orientifol
Externí odkaz:
http://arxiv.org/abs/1212.5178
Autor:
Danielsson, Ulf H.
In this paper we propose a mechanism that protects theories violating a holographic bound suggested in arXiv:1203.5476 from developing accelerated expansion. The mechanism builts on work on transplanckian physics, and a non-trivial choice of vacuum s
Externí odkaz:
http://arxiv.org/abs/1204.3311
In this note we discuss a possible resolution of the flux singularities associated with the insertion of branes in backgrounds supported by fluxes that carry charges opposite to the branes. We present qualitative arguments that such a setup could be
Externí odkaz:
http://arxiv.org/abs/1202.1132
Autor:
Blåbäck, Johan, Danielsson, Ulf H., Junghans, Daniel, Van Riet, Thomas, Wrase, Timm, Zagermann, Marco
Publikováno v:
JHEP 1202:025,2012
We improve on the understanding of the backreaction of anti-D6-branes in a flux background that is mutually BPS with D6-branes. This setup is analogous to the study of the backreaction of anti-D3-branes inserted in the KS throat, but does not require
Externí odkaz:
http://arxiv.org/abs/1111.2605
Autor:
Blåbäck, Johan, Danielsson, Ulf H., Junghans, Daniel, Van Riet, Thomas, Wrase, Timm, Zagermann, Marco
Publikováno v:
JHEP 1108:105,2011
In this paper we investigate the localisation of SUSY-breaking branes which, in the smeared approximation, support specific non-BPS vacua. We show, for a wide class of boundary conditions, that there is no flux vacuum when the branes are described by
Externí odkaz:
http://arxiv.org/abs/1105.4879