| 1. |
- Shiu, Gary, et al.
(författare)
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Connecting flux vacua through scalar field excursions
- 2024
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 109:6
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Tidskriftsartikel (refereegranskat)abstract
- We show how flux vacua that differ from each other in flux quanta can be seen as different vacua in a single scalar potential of an enlarged field space, which resolves the separation by thin domain walls. This observation, which is motivated by the anti–de Sitter distance conjecture, allows one to compute distances between different vacua using the usual field-space metric. We verify for explicit examples such as scale-separated IIA flux vacua and the IIB Freund-Rubin vacua that the distance conjecture (for scalar fields) is satisfied and that the asymptotic directions in the enlarged field space are indeed hyperbolic. This enlarged field space contains the tachyon fields on the unstable ˜Dp-branes of type II string theory, which can induce the brane charges of the stable D-branes. We suggest that requiring continuous interpolations refines the cobordism conjecture and postdicts the existence of unstable ˜Dp-branes.
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| 2. |
- Blaback, Johan, et al.
(författare)
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Lifshitz backgrounds from 10d supergravity
- 2010
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :2, s. 095-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate whether 4-dimensional static and cosmological Lifshitz solutions can be found from deforming the existing (A)dS(4) compactifications in IIA and IIA. supergravity. Using a well motivated compactification Ansatz on SU(3)-structure manifolds with 19 undetermined parameters we demonstrate that this is not the case in ordinary IIA supergravity, thereby generalising previous nogo results in different ways. On the other hand, for IIA* we construct explicit cosmological Lifshitz solutions. We also consider solutions with non-constant scalars and are able to find simple static and cosmological Lifshitz solutions in IIB* supergravity and a Euclidean Lifshitz solution in ordinary Euclidean IIB supergravity, which is similar to a non-extremal deformation of the D-instanton. The latter solutions have z = -2.
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| 3. |
- Blåbäck, Johan, et al.
(författare)
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(Anti-)brane backreaction beyond perturbation theory
- 2012
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; 2012:2, s. 025-
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Tidskriftsartikel (refereegranskat)abstract
- 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 us to smear the anti-branes or do a perturbative analysis around the BPS background. We solve the full equations of motion near the anti-D6-branes and show that only two boundary conditions are consistent with the equations of motion. Upon invoking a topological argument we eliminate the boundary condition with regular H flux since it cannot lead to a solution that approaches the right kind of flux away from the anti-D6-branes. This leaves us with a boundary condition which has singular, but integrable, H flux energy density.
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| 4. |
- Blåbäck, Johan, et al.
(författare)
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BPS domain walls from backreacted orientifolds
- 2014
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :5, s. 040-
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Tidskriftsartikel (refereegranskat)abstract
- Compactifications with D-brane and orientifold sources lead to standard gauged supergravity theories if the sources are smeared over the internal directions. It is therefore of interest to find how the solutions described by the gauged supergravity are altered by properly localising the sources. In this paper we analyse this for BPS domain wall solutions in the seven-dimensional gauged supergravity obtained from an O6 toroidal orientifold in massive IIA supergravity. This is one of the simplest no-scale supergravities that can be constructed and analysed in full detail. We find the BPS domain walls when the O6 planes are smeared. When the O6 planes are localised the domain wall solutions live in a warped compactification and we present the first-order equations these domain walls obey in 10 dimensions. In order to get explicit expressions we also consider the non-compact versions of the solutions for which the O6 planes have been traded for D6 branes and we recover the gauged supergravity expressions for the domain walls in the leading terms of the warp factor. Through T-duality we obtain partially localised solutions for compactifications to four dimensions using O3 planes with 3-form fluxes.
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| 5. |
- Blåbäck, Johan, et al.
(författare)
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Resolving anti-brane singularities through time-dependence
- 2013
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :2, s. 61-
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Tidskriftsartikel (refereegranskat)abstract
- 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 unstable both in the closed and open string sector. The singularities in the fluxes then get naturally resolved by taking the true solution to be a time-dependent process in which flux gets attracted towards the brane and subsequently annihilates.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 unstable both in the closed and open string sector. The singularities in the fluxes then get naturally resolved by taking the true solution to be a time-dependent process in which flux gets attracted towards the brane and subsequently annihilates.
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| 6. |
- Blåbäck, Johan, et al.
(författare)
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Smeared versus localised sources in flux compactifications
- 2010
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :12, s. 043-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate whether vacuum solutions in flux compactifications that are obtained with smeared sources (orientifolds or D-branes) still survive when the sources are localised. This seems to rely on whether the solutions are BPS or not. First we consider two sets of BPS solutions that both relate to the GKP solution through T-dualities: (p + 1)-dimensional solutions from spacetime-filling Op-planes with a conformally Ricci-flat internal space, and p-dimensional solutions with Op-planes that wrap a 1-cycle inside an everywhere negatively curved twisted torus. The relation between the solution with smeared orientifolds and the localised version is worked out in detail. We then demonstrate that a class of non-BPS AdS(4) solutions that exist for IASD fluxes and with smeared D3-branes (or analogously for ISD fluxes with anti-D3-branes) does not survive the localisation of the (anti) D3-branes. This casts doubts on the stringy consistency of non-BPS solutions that are obtained in the limit of smeared sources.
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| 7. |
- Blåbäck, Johan, et al.
(författare)
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The problematic backreaction of SUSY-breaking branes
- 2011
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :8, s. 105-
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Tidskriftsartikel (refereegranskat)abstract
- 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 a genuine delta-function. Even more, we find that the smeared solution is the unique solution with a regular brane profile. Our setup consists of a non-BPS AdS(7) solution in massive IIA supergravity with smeared anti-D6-branes and fluxes T-dual to ISD fluxes in IIB supergravity.
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| 8. |
- Chemissany, Wissam, et al.
(författare)
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Black holes as generalised Toda molecules
- 2011
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Ingår i: Nuclear Physics B. - : Elsevier BV. - 0550-3213 .- 1873-1562. ; 843, s. 413-428
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Tidskriftsartikel (refereegranskat)abstract
- In this note we compare the geodesic formalism for spherically symmetric black hole solutions with the black hole effective potential approach. The geodesic formalism is beneficial for symmetric supergravity theories since the symmetries of the larger target space leads to a complete set of commuting constants of motion that establish the integrability of the geodesic equations of motion, as shown in arXiv:1007.3209. We point out that the integrability lifts straightforwardly to the integrability of the equations of motion with a black hole potential. This construction turns out to be a generalisation of the connection between Toda molecule equations and geodesic motion on symmetric spaces known in the mathematics literature. We describe in some detail how this generalisation of the Toda molecule equations arises.
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| 9. |
- Chemissany, Wissam, et al.
(författare)
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Einstein branes
- 2011
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :10, s. 002-
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Tidskriftsartikel (refereegranskat)abstract
- We generalise the standard, flat p-brane solutions sourced by a dilaton and a form field, by taking the worldvolume to be a curved Einstein space, such as (anti-)de Sitter space. Our method is based on reducing the p-branes to domain walls and then allowing these domain walls to be curved. For de Sitter worldvolumes this extends some recently constructed warped de Sitter non-compactifications. We restrict our analysis to solutions that possess scaling behavior and demonstrate that these scaling solutions are near-horizon limits of a more general solution. Finally, our framework can equally be used for spacelike branes and the uplift of the domain wall/cosmology correspondence becomes in this context a more general timelike/spacelike brane correspondence.
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| 10. |
- Chemissany, Wissam, et al.
(författare)
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The Full integration of black hole solutions to symmetric supergravity theories
- 2010
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Ingår i: Nuclear Physics B. - : Elsevier BV. - 0550-3213 .- 1873-1562.
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Tidskriftsartikel (refereegranskat)abstract
- We prove that all stationary and spherical symmetric black hole solutions to theories with symmetric target spaces are integrable and we provide an explicit integration method. This exact integration is based on the description of black hole solutions as geodesic curves on the moduli space of the theory when reduced over the timelike direction. These geodesic equations of motion can be rewritten as a specific Lax pair equation for which mathematicians have provided the integration algorithms when the initial conditions are described by a diagonalizable Lax matrix. We comment on BPS versus non-BPS extremal black holes in this setup. The explicit details, such as a full integration of the STU-model and the non-diagonalizable integration algorithm, is left for a future work and instead some simple examples to illustrate our point are presented.
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