Simon Fraser University
SFU Cosmology Seminars

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Tuesday, 1 April 2008, 12:30 in IRMACS

Dr. James Zibin (UBC)

Restraining void models for cosmological acceleration

The last decade has seen the compilation of strong evidence that the expansion of the Universe is currently accelerating. The source for this acceleration is still a mystery, although probably the simplest view is that it is caused by a cosmological constant. One alternative explanation which requires no new matter fields or modifications of gravity, but discards the Copernican Principle, involves a large nonlinear underdensity centred near us. It is known that such a void can mimic some of the data by replacing increasing expasion rate in time with increasing expansion rate towards the void centre. I discuss the difficulties that void models face, from the philosophical to the observational. I also lay out a general relativistic framework for the evolution of linear perturbations on a spherical void background aimed at confronting with data.

Seminars in 2007:

2007-10-05 14:30 in K9500 - Douglas Scott (UBC): The Standard Cosmological Model (physics colloquium)
2007-10-23 14:30 in SSB7172 - Wan-Il Park (KAIST): A scenario of baryogenesis compatible with thermal inflation, and preheating
2007-10-30 14:30 in SSB7172 - Alessandra Silvestri (Syracuse University): Scale-dependent growth of structure in viable f(R) theories
2007-11-13 14:30 in SSB7172 - Gong-Bo Zhao (SFU): Dark energy perturbation and its application on cosmology
2007-11-29 14:30 in IRMACS - Henk Hoekstra (University of Victoria): Weak lensing by large scale structure
2008-01-15 12:30 in IRMACS - Mustafa Amin (Stanford/KIPAC): A framework for probing gravity and dark energy on cosmological scales
2008-01-22 12:30 in IRMACS - Richard Battye (University of Manchester): Constraints on inflation models which predict cosmic strings
2008-01-24 13:30 in SSB7172 - John Moffat (University of Toronto/Perimeter): Modified gravity and its consequences for astronomy, astrophysics and cosmology
2008-01-31 13:00 in AQ4150 - Saurya Das (University of Lethbridge): Black holes and the problem of information loss (CAP Lecture)
2008-02-05 12:30 in IRMACS - Aaron Berndsen (SFU): Long-lived relics in warped reheating
2008-02-07 10:30 in IRMACS - Scott Dodelson (Fermilab): Dark matter vs. modified gravity
2008-02-07 13:30 in SSB7172 - Scott Dodelson (Fermilab): Fundamental physics from space (special colloquium)
2008-02-22 14:30 in AQ3181 - Andrei Frolov (SFU): Simulating the Big Bang (physics colloquium)
2008-03-28 14:30 in AQ3181 - Alexander Vilenkin (Tufts University): Many worlds in one (physics colloquium)
2008-04-01 12:30 in IRMACS - James Zibin (UBC): Restraining void models for cosmological acceleration
2008-05-13 11:00 in P8445B - Mark Wyman (Perimeter Institute): N-body Degravitation
2008-08-14 11:00 in SSB7109 - Prashanth Jaikumar (Institute of Mathematical Sciences, CIT, India): Astrophysics of dense quark matter

[ See complete seminar archives | iCal feed ]

Modified by Andrei Frolov <frolov@sfu.ca> on 2023-11-01