117 citations · 1.4k across the 55 of their papers we have counts for
55 papers
Quantum Transitions, Detailed Balance, Black Holes and Nothingness
Sebastian Cespedes, Senarath de Alwis, Francesco Muia +1
We consider vacuum transitions by bubble nucleation among 4D vacua with different values and signs of the cosmological constant , including both up and down tunnelings. Followin…
Revisiting Vacuum decay in Field Theory
S. P. de Alwis
We revisit the formalism for tunneling in quantum field theory developed by Coleman and collaborators. In particular using the generalization of WKB methods for tunneling in quantu…
Comments on Entropy Calculations in Gravitational Systems
S. P. de Alwis
We discuss the logic of, and some puzzles in, the various approaches to thermodynamics of gravitational systems. In particular the blackhole, deSitter (dS), black hole in dS (SdS)…
Density Perturbations and Primordial Non-Gaussianities in a Closed Universe
Sebastian Cespedes, Senarath de Alwis, Francesco Muia +1
The spatial curvature of the universe is not yet known. Even though at present the Universe is very close to being essentially flat and most signatures of curvature appear to have…
Quantum Transitions Between Minkowski and de Sitter Spacetimes
Senarath P. de Alwis, Francesco Muia, Veronica Pasquarella +1
Quantum transitions among de Sitter and Minkowski spacetimes through bubble nucleation are revisited using the Hamiltonian formalism. We interpret tunnelling probabilities as relat…
Robust Inflation from Fibrous Strings
C. P. Burgess, M. Cicoli, S. de Alwis +1
Successful inflationary models should (i) describe the data well; (ii) arise generically from sensible UV completions; (iii) be insensitive to detailed fine-tunings of parameters a…
Cosmological fluctuations: Comparing Quantum and Classical Statistical and Stringy Effects
S. P. de Alwis
The theory of cosmological fluctuations assumes that the pre-inflationary state of the universe was the quantum vacuum of a scalar field(s) coupled to gravity. The observed cosmic…
On KKLT/CFT and LVS/CFT Dualities
Senarath de Alwis, Rajesh Kumar Gupta, Fernando Quevedo +1
We present a general discussion of the properties of three dimensional CFT duals to the AdS string theory vacua coming from type IIB Calabi-Yau flux compactifications. Both KKLT an…
On Moduli Spaces in Supergravity
Senarath de Alwis, Jan Louis, Liam McAllister +2
We study the structure of the supersymmetric moduli spaces of and supergravity theories in backgrounds. In the case, the moduli space…
Comment on "Anomaly Mediation from Unbroken Supergravity"
S. P. de Alwis
I argue that ArXiv:1307.3251 is based on a misunderstanding of the role of Weyl transformations in local off-shell supersymmetry and what constitutes a true symmetry of the theory.
Stability, Tunneling and Flux Changing de Sitter Transitions in the Large Volume String Scenario
S. de Alwis, R. K. Gupta, E. Hatefi +1
We study the non-perturbative stability of the Large Volume Scenario (LVS) of IIB string compactifications, by analysing transitions mediated by the Brown-Teitelboim (BT) brane nuc…
Heterotic Moduli Stabilisation
Michele Cicoli, Senarath de Alwis, Alexander Westphal
We perform a systematic analysis of moduli stabilisation for weakly coupled heterotic string theory compactified on manifolds which are Calabi-Yau up to alpha' effects. We review h…
A Local Evaluation of Global Issues in SUSY breaking
S. P. de Alwis
It is well known that there are different global (i.e. ) limits of N=1 supergravity. We distinguish between these limits and their relevance to low energy p…
Gauge Threshold Corrections and Field Redefinitions
S. P. de Alwis
We review the argument for field redefinitions arising from threshold corrections to heterotic string gauge couplings, and the relation between the linear and the chiral multiplet.…
AMSB and the Logic of Spontaneous SUSY Breaking
S. P. de Alwis
A cardinal principle of any theory of spontaneous () supersymmetry breaking, is that the order parameter is a linear combination of the F and D terms. Also as long as t…
Constraints on LVS Compactifications of IIB String Theory
S. P. de Alwis
We argue that once all theoretical and phenomenological constraints are imposed on the different versions of the Large Volume Scenario (LVS) compactifications of type IIB string th…
Dark Matter density and the Higgs mass in LVS String Phenomenology
Senarath de Alwis, Kevin Givens
The Large Volume Scenario for getting a non-supersymmetric vacuum in type IIB string theory leads, through the Weyl anomaly and renormalization group running, to an interesting phe…
A Unified Approach to Supersymmetry Breaking
S. P. de Alwis
General formulae for the soft SUSY breaking terms, valid in any SUGRA context, were derived in the mid-nineties. Since SUSY is not expected to have quantum anomalies, they should b…
Physical Vacua in IIB Compactifications with a Single Kaehler Modulus
Senarath de Alwis, Kevin Givens
We search for phenomenologically viable vacua of IIB string flux compactifications on Calabi-Yau orientifolds with a single Kaehler modulus. We perform both analytic studies and nu…
A Comparison of Supersymmetry Breaking and Mediation Mechanisms
S. P. de Alwis
We give a unified treatment of different models of supersymmetry breaking and mediation from a four dimensional effective field theory standpoint. In particular a comparison betwee…
Gaugino Anomaly Mediated SUSY Breaking: phenomenology and prospects for the LHC
Howard Baer, Senarath de Alwis, Kevin Givens +2
We examine the supersymmetry phenomenology of a novel scenario of supersymmetry (SUSY) breaking which we call Gaugino Anomaly Mediation, or inoAMSB. This is suggested by recent wor…
Classical and Quantum SUSY Breaking Effects in IIB Local Models
S. P. de Alwis
We discuss the calculation of soft supersymmetry breaking terms in type IIB string theoretic models in the Large Volume Scenario (LVS). The suppression of FCNC gives a lower bound…
Heterotic Strings on Generalized Calabi-Yau Manifolds and Kaehler Moduli Stabilization
S. P. de Alwis
Compactifications of heterotic string theory on Generalized Calabi-Yau manifolds have been expected to give the same type of flexibility that type IIB compactifications on Calabi-Y…
Moduli potentials in string compactifications with fluxes: mapping the Discretuum
R. Brustein, S. P. de Alwis
We find de Sitter and flat space solutions with all moduli stabilized in four dimensional supergravity theories derived from the heterotic and type II string theories, and explain…