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PERIMETER INSTITUTE RECORDED SEMINAR ARCHIVE

PIRSA:C07008 - Excursions in the Dark Workshop - 2007PODCAST Subscribe to podcast

Excursions in the Dark Workshop

Organizer(s): Justin Khoury  

Collection URL: http://pirsa.org/C07008


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PIRSA:07050028  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Dark Energy from variation of the fundamental scale
Speaker(s): Christof Wetterich
Abstract: We explore the hypothesis that a dynamical dark energy is related to a time-variation of the fundamental mass scale. A dilatation anomaly induced by quantum fluctuations could explain the small value of the present dark energy. Reformulated as a scalar field theory this would predict a quintessence ... read more
Date: 18/05/2007 - 9:00 am

PIRSA:07050029  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Embedding Quintessence in Spontaneously Broken N=1 Supergravity
Speaker(s): Philippe Brax
Abstract: I will present the embedding of runaway quintessence models in supergravity coupled to observable matter and hidden supersymmetry breaking. Serious obstructions appear either in the gravitational sector of the theory or cosmologically. Alternatives will be discussed.
Date: 18/05/2007 - 11:00 am

PIRSA:07050031  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Dynamics of Linear Perturbations in Modified Gravity Theories
Abstract: A modification of Gravity in the low-curvature regime may account for the late time acceleration of our universe, and is therefore an interesting alternative to Dark Energy.In such models, the modified Einstein equations admit self-accelerated solutions in the presence of negligible matter. At the l... read more
Date: 18/05/2007 - 11:30 am

PIRSA:07050030  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Two Topics on the Accelerating Universe
Speaker(s): Gregory Gabadadze
Abstract:
Date: 18/05/2007 - 4:00 pm

PIRSA:07050032  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Dark Energy and Neutrino Mass
Speaker(s): Urbano Franca
Abstract: One of the possible explanations for the current acceleration of the universe comes from a coupling between the Dark Energy and the Neutrino sectors. This coupling causes the neutrino mass to vary with cosmic time, what opens a new window to constrain this dark energy candidate. In this work, we ana... read more
Date: 18/05/2007 - 5:00 pm

PIRSA:07050033  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Explorations in Supersymmetric Large Extra Dimensions
Speaker(s): Susha Parameswaran
Abstract: Brane worlds may provide insight into the cosmological constant problem because a large vacuum energy on the brane can curve the extra dimensions rather than the local 4D spacetime. Moreover, such models with supersymmetric large extra dimensions reveal a tantalizing numerology, in which the size of... read more
Date: 18/05/2007 - 5:30 pm

PIRSA:07050035  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Large Extra Dimensions and Darkness From String Theory
Speaker(s): Fernando Quevedo
Abstract:
Date: 19/05/2007 - 11:00 am

PIRSA:07050036  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Non-Anthropic Approaches to the String Landscape
Speaker(s): G. Watson
Abstract: We consider the effect that dynamical selection principles could have on the string landscape and for determining the value of the cosmological constant. The underlying symmetries of string theory, along with the dynamics of moduli in the low energy effective field theory, seem to suggest that not a... read more
Date: 19/05/2007 - 4:00 pm

PIRSA:07050037  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Nonlinear Structure Formation and Apparent Acceleration: An Investigation
Speaker(s): Alessio Notari
Abstract: We present analytically solvable nonlinear models of structure formation in a Universe with only dust, using LTB solutions. We show that the luminosity distance-redshift relation has significant corrections at low redshift (Doppler effect). We discuss different possibilities that could further enhan... read more
Date: 19/05/2007 - 4:30 pm

PIRSA:07050038  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Why the Vacuum Energy is Enormous (Just Not Here and Now)
Speaker(s): Anthony Aguirre
Abstract:
Date: 19/05/2007 - 5:00 pm

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