119 citations · 943 across the 32 of their papers we have counts for
32 papers
Limits on the Statistical Description of Charged de Sitter Black Holes
Lars Aalsma, Puxin Lin, Jan Pieter van der Schaar +2
The thermodynamics of de Sitter black holes is complicated by the presence of two horizons and the absence of a globally defined timelike Killing vector. The standard choice of the…
Quasinormal Modes and the Switchback Effect in Schwarzschild-de Sitter
Mir Mehedi Faruk, Facundo Rost, Jan Pieter van der Schaar
We study the causal structure of Schwarzschild-de Sitter (SdS), including shock wave perturbations, in using reflected null ray trajectories, either through the interior blac…
Static sphere observers and geodesics in Schwarzschild-de Sitter spacetime
Mir Mehedi Faruk, Edward Morvan, Jan Pieter van der Schaar
We analyze null- and spacelike radial geodesics in Schwarzschild-de Sitter spacetime connecting two conjugate static sphere observers, i.e. free-falling observers at a fixed radius…
Extremal Black Hole Decay in de Sitter Space
Lars Aalsma, Jan Pieter van der Schaar, Manus Visser
The decay of extremal charged black holes has been a useful guidance to derive consistency conditions in quantum gravity. In de Sitter space it has been argued that requiring (extr…
Axion-de Sitter wormholes
Sergio E. Aguilar-Gutierrez, Thomas Hertog, Rob Tielemans +2
We construct wormholes supported by axion flux in the presence of a positive cosmological constant. The solutions describe compact, one-handle bodies colloquially known as kettlebe…
Holographic duals of the * gauge theory
Jay Armas, Giorgos Batzios, Jan Pieter van der Schaar
We use the long-wavelength effective theory of black branes (blackfold approach) to perturbatively construct holographic duals of the vacua of the * supersymmetric g…
Action, entropy and pair creation rate of charged black holes in de Sitter space
Edward K. Morvan, Jan Pieter van der Schaar, Manus R. Visser
We compute and clarify the interpretation of the on-shell Euclidean action for Reissner-Nordström black holes in de Sitter space. We show the on-shell action is minus the sum of th…
Late-Time Correlators and Complex Geodesics in de Sitter Space
Lars Aalsma, Mir Mehedi Faruk, Jan Pieter van der Schaar +2
We study two-point correlation functions of a massive free scalar field in de Sitter space using the heat kernel formalism. Focusing on two operators in conjugate static patches we…
On the Euclidean Action of de Sitter Black Holes and Constrained Instantons
Edward K. Morvan, Jan Pieter van der Schaar, Manus R. Visser
We compute the on-shell Euclidean action of Schwarzschild-de Sitter black holes, and take their contributions in the gravitational path integral into account using the formalism of…
Shocks and Information Exchange in de Sitter Space
Lars Aalsma, Alex Cole, Edward Morvan +2
We discuss some implications of recent progress in understanding the black hole information paradox for complementarity in de Sitter space. Extending recent work by two of the auth…
Extremal Tunneling and Anti-de Sitter Instantons
Lars Aalsma, Jan Pieter van der Schaar
We rederive and extend the amplitude for charged spherical shells tunneling through the outer horizon of charged black holes. In particular, we explicitly confirm that an effective…
Constrained superfields on metastable anti-D3-branes
Lars Aalsma, Jan Pieter van der Schaar, Bert Vercnocke
We study the effect of brane polarization on the supersymmetry transformations of probe anti-D3-branes at the tip of a Klebanov-Strassler throat geometry. As is well known, the pro…
Chaotic inflation limits for non-minimal models with a Starobinsky attractor
Benjamin Mosk, Jan Pieter van der Schaar
We investigate inflationary attractor points by analyzing non-minimally coupled single field inflation models in two opposite limits; the `flat' limit in which the first derivative…
Derivation of the Null Energy Condition
Maulik Parikh, Jan Pieter van der Schaar
We derive the null energy condition, understood as a constraint on the Einstein-frame Ricci tensor, from worldsheet string theory. For a closed bosonic string propagating in a curv…
Rolling Through a Vacuum
Jan Pieter van der Schaar, I-Sheng Yang
We clarify under what conditions slow-roll inflation can continue almost undisturbed, while briefly evolving through a (semi-classically) metastable false vacuum. Furthermore, we l…
WMAP 7 Constraints on Oscillations in the Primordial Power Spectrum
P. Daniel Meerburg, Ralph Wijers, Jan Pieter van der Schaar
We use the WMAP 7 data to place constraints on oscillations supplementing an almost scale-invariant primordial power spectrum. Such oscillations are predicted by a variety of model…
Minimal cut-off vacuum state constraints from CMB bispectrum statistics
P. Daniel Meerburg, Jan Pieter van der Schaar
In this short note we translate the best available observational bounds on the CMB bispectrum amplitudes into constraints on a specific scale-invariant New Physics Hypersurface (NP…
Bispectrum signatures of a modified vacuum in single field inflation with a small speed of sound
P. Daniel Meerburg, Jan Pieter van der Schaar, Mark G. Jackson
Deviations from the Bunch-Davies vacuum during an inflationary period can leave a testable imprint on the higher-order correlations of the CMB and large scale structures in the Uni…
Exact spectrum of scalar field perturbations in a radiation deformed closed de Sitter universe
Sash Sarangi, Koenraad Schalm, Gary Shiu +1
We observe that the equation of motion for a free scalar field in a closed universe with radiation and a positive cosmological constant is given by Lamé's equation. Computing the e…
Decoupling in an expanding universe: boundary RG-flow affects initial conditions for inflation
Koenraad Schalm, Gary Shiu, Jan Pieter van der Schaar
We study decoupling in FRW spacetimes, emphasizing a Lagrangian description throughout. To account for the vacuum choice ambiguity in cosmological settings, we introduce an arbitra…
Inflationary Perturbations from Deformed CFT
Jan Pieter van der Schaar
We present a new method to calculate the spectrum of (slow-roll) inflationary perturbations, inspired by the conjectured dS/CFT correspondence. We show how the standard result for…
De Sitter Holography and the Cosmic Microwave Background
Finn Larsen, Jan Pieter van der Schaar, Robert G. Leigh
We interpret cosmological evolution holographically as a renormalisation group flow in a dual Euclidean field theory, as suggested by the conjectured dS/CFT correspondence. Inflati…
Reduction of open membrane moduli
Eric Bergshoeff, Jan Pieter van der Schaar
We perform a general reduction of the open membrane metric in a worldvolume direction of the M5-brane. Using reduction rules analogous to the bulk, we show that the open membrane m…
The Reduced Open Membrane Metric
Jan Pieter van der Schaar
We discuss the reduction of the open membrane metric and determine the (previously unknown) conformal factor. We also construct SL(2,R) invariant open string metrics and complex op…