767 citations · 17k across the 373 of their papers we have counts for
15 papers · 1 filter
Adiabatic and Isocurvature Perturbations for Multifield Generalized Einstein Models
Fabrizio Di Marco, Fabio Finelli, Robert Brandenberger
Low energy effective field theories motivated by string theory will likely contain several scalar moduli fields which will be relevant to early Universe cosmology. Some of these fi…
Trans-Planckian Physics and Inflationary Cosmology
Robert H. Brandenberger
Due to the quasi-exponential red-shifting which occurs during an inflationary period in the very early Universe, wavelengths which at the present time correspond to cosmological le…
Back Reaction of Cosmological Perturbations and the Cosmological Constant Problem
Robert H. Brandenberger
The presence of cosmological fluctuations influences the background cosmology in which the perturbations evolve. This back-reaction arises as a second order effect in the cosmologi…
Principles, Progress and Problems in Inflationary Cosmology
Robert H. Brandenberger
Inflationary cosmology has become one of the cornerstones of modern cosmology. Inflation was the first theory within which it was possible to make predictions about the structure o…
On T-Duality in Brane Gas Cosmology
Timon Boehm, Robert Brandenberger
In the context of homogeneous and isotropic superstring cosmology, the T-duality symmetry of string theory has been used to argue that for a background space-time described by dila…
On the Construction of Nonsingular Pre-Big-Bang and Ekpyrotic Cosmologies and the Resulting Density Perturbations
Shinji Tsujikawa, Robert Brandenberger, Fabio Finelli
We consider the construction of nonsingular Pre-Big-Bang and Ekpyrotic type cosmological models realized by the addition to the action of specific higher-order terms stemming from…
Isotropization in Brane Gas Cosmology
Scott Watson, Robert H. Brandenberger
Brane Gas Cosmology (BGC) is an approach to unifying string theory and cosmology in which matter is described by a gas of strings and branes in a dilaton gravity background. The Un…
Stabilization of the Electroweak Z String in the Early Universe
Michiyasu Nagasawa, Robert Brandenberger
The standard electroweak theory admits a string solution, the Z string, in which only the electrically neutral Higgs fields are excited. This solution is unstable at zero temperatu…
Back Reaction And Local Cosmological Expansion Rate
Ghazal Geshnizjani, Robert Brandenberger
We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a…
Noncommutative Spacetime, Stringy Spacetime Uncertainty Principle, and Density Fluctuations
Robert Brandenberger, Pei-Ming Ho
We propose a variation of spacetime noncommutative field theory to realize the stringy spacetime uncertainty relation without breaking any of the global symmetries of the homogeneo…
On Signatures of Short Distance Physics in the Cosmic Microwave Background
Robert H. Brandenberger, Jerome Martin
Following a self-contained review of the basics of the theory of cosmological perturbations, we discuss why the conclusions reached in the recent paper by Kaloper et al are too pes…
Microwave Background Constraints on Decaying Defects
Robert H. Brandenberger, Brandon Carter, Anne-Christine Davis
Embedded defects are predicted in a host of particle physics theories, in particular in the standard electroweak theory. They can be stabilized by interactions with the cosmologica…
Thermal Stabilisation of Superconducting Sigma Strings and their Drum Vortons
Brandon Carter, Robert H. Brandenberger, Anne-Christine Davis
We discuss various issues related to stabilized embedded strings in a thermal background. In particular, we demonstrate that such strings will generically become superconducting at…
The Corley-Jacobson dispersion relation and trans-Planckian inflation
Jerome Martin, Robert H. Brandenberger
In this Letter we study the dependence of the spectrum of fluctuations in inflationary cosmology on possible effects of trans-Planckian physics, using the Corley/Jacobson dispersio…
Trans-Planckian Physics and the Spectrum of Fluctuations in a Bouncing Universe
Robert H Brandenberger, Sergio E. Joras, Jerome Martin
In this paper, we calculate the spectrum of scalar field fluctuations in a bouncing, asymptotically flat Universe, and investigate the dependence of the result on changes in the ph…