McGill University  Department of Physics
Talks by Robert Brandenberger
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String Theory and Nonsingular Cosmology
Robert Brandenberger
McGill University  Department of Physics
I will argue that in the context of string theory, the Big Bang singularity of standard and inflationary cosmology is automatically resolved. To see this at the level of an effective field theory, ideas from "Double Field Theory" are useful.
Challenges for Bouncing Cosmologies
Robert Brandenberger
McGill University  Department of Physics
I will review various approaches to bouncing cosmologies and will discuss challenges which the different approaches face.
Is BMode Polarization of the CMB the Holy Grail of Inflation?
Robert Brandenberger
McGill University  Department of Physics
I will discuss why the search for BMode Polarization of the Cosmic Microwave Background (CMB) is very important for early universe cosmology, but that a discovery of such a polarization mode is in no way a confirmation of inflationary cosmology.
Quantum Gravity Effects in the (Early and Late) Universe

Stephon Alexander Brown University

Daniel Sudarsky Universidad Nacional Autónoma De Mexico (UNAM)

Daniel Litim University of Sussex

Robert Brandenberger McGill University  Department of Physics
Quantum Gravity at the origin of seeds of cosmic
structure?
Photons and Quantum Gravity in Astrophysics

Robert Nemiroff Michigan Technological University

Giovanni AmelinoCamelia Sapienza Università di Roma  Dipartimento di Fisica

Niayesh Afshordi University of Waterloo

Joao Magueijo Imperial College London

Alfio Bonanno INAF, Catania

Robert Brandenberger McGill University  Department of Physics
Asymptotically safe inflation and CMB polarization
The presence of complex critical exponents in the scaling behavior of the Newton constant and Cosmological constant has dramatic consequences at the inflation scale. In particular an infinite number of unstable deSitter vacua emerges from an effective quantum gravitational action. In this framework, the possibility of detecting specific signaturesof a nongaussian fixed point of the gravitational interactions in the CMB polarization spectrum will then be discussed.
The presence of complex critical exponents in the scaling behavior of the Newton constant and Cosmological constant has dramatic consequences at the inflation scale. In particular an infinite number of unstable deSitter vacua emerges from an effective quantum gravitational action. In this framework, the possibility of detecting specific signaturesof a nongaussian fixed point of the gravitational interactions in the CMB polarization spectrum will then be discussed.
Looking for Cosmic Strings in New Observational Windows
Robert Brandenberger
McGill University  Department of Physics
Cosmic strings are predicted to arise in both inflationary
and noninflationary cosmological models. The signatures of
such strings will stand out particularly well at higher
redshifts. I will discuss how to look for these signatures
in CMB redshift and polarization maps and in 21cm redshift
surveys.
Background Cosmology and Cosmological Perturbations in HoravaLifshitz Gravity
Robert Brandenberger
McGill University  Department of Physics
Meet a Scientist  Prof. Robert Brandenberger
Robert Brandenberger
McGill University  Department of Physics
Cosmology as a natural meeting ground for fundamental theory (e.g. superstring theory or quantum gravity) and observations. Exploring how seeds laid down in the very early universe developed into the large scale structure we observe in the universe today.
Holography in String Gas Cosmology
Robert Brandenberger
McGill University  Department of Physics
I will review the string gas scenario of structure formation, stressing the role which holography plays. I will also discuss another way of obtaining a scaleinvariant spectrum of cosmological perturbations (with specific signatures in the bispectrum) which may be realizable in scenarios based on the AdS/CFT correspondence which can resolve the cosmological singularity.
Cosmology of the LeeWick Model
Robert Brandenberger
McGill University  Department of Physics
The LeeWick model has recently been put forwards as an alternative to supersymmetry for solving the hierarchy problem of particle physics. I will show that, modulo important consistency questions, coupling the LeeWick model to cosmology leads to a bouncing universe cosmology with a scaleinvariant spectrum of cosmological fluctuations emerging from quantum vacuum fluctuations in the contracting phase.