Simon Fraser University
SFU Cosmology Seminars

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Tuesday, 12 November 2013, 14:00 in P8445B

Jun-Qi Guo (SFU)

Spherical collapse in f(R) gravity

The spherical scalar collapse in f(R) gravity is studied numerically. The f(R) theory is a modification of general relativity at low curvature scale and the Ricci curvature scalar decreases when the physical scalar field collapses to form a black hole. Consequently, the gravity transits from general relativity to f(R) gravity, and the scalar degree of freedom f' is released from a coupled state to a light state. Due to the gravity from the scalar sphere and the lightness of f', f' crosses the minimum of the potential and approaches zero near the singularity of the black hole. Near the singularity, in the equations of motion for the metric components and the scalar fields, the spacial derivative terms are negligible compared to the time derivative terms; the equations of motion are decoupled, transferring from partial differential equations to ordinary differential equations with respect to the coordinate time. The behaviors of the metric components and the scalar fields are described by the Kanser solutions. These results confirm the BKL conjecture. The final state of the scalar collapse in f(R) gravity will be discussed.

Seminars in 2013:

2013-09-10 14:00 in P8445B - Andrei Frolov (SFU): Intermittent non-Gaussianity
2013-09-20 14:30 in AQ3150 - Christopher Stubbs (Harvard University): The dark energy crisis in the longer term (physics colloquium)
2013-10-01 14:00 in P8445B - Ali Narimani (UBC): Minimal parameterizations for modified gravity
2013-10-04 14:30 in AQ3150 - Joseph Polchinski (KITP): The black hole information paradox, alive and kicking (physics colloquium)
2013-10-08 14:00 in P8445B - Yin-Zhe Ma (UBC): Cosmic peculiar velocity field
2013-10-22 14:00 in P8445B - Alireza Hojjati (SFU): Cosmology with strong lensing time delays
2013-10-29 14:00 in P8445B - Levon Pogosian (SFU): Primordial magnetism in CMB polarization
2013-11-01 14:30 in AQ3150 - Neil Turok (Perimeter Institute): On quantum tunnelling (physics colloquium)
2013-11-12 14:00 in P8445B - Jun-Qi Guo (SFU): Spherical collapse in f(R) gravity
2013-11-19 14:00 in P8445B - Jes Ford (UBC): Weighing galaxy clusters with weak lensing magnification
2014-01-28 14:00 in P8445B - Ivan Agullo (Louisiana State University): Conformal anomaly and primordial magnetic fields
2014-03-04 14:00 in P8445B - Thomas Kephart (Vanderbilt University): Helicity conservation and generalized Beltrami fields
2014-04-08 14:00 in P8445B - Zhiqi Huang (CITA, University of Toronto): Inflation trajectories after Planck and BICEP2
2014-05-06 16:00 in Saywell 10081 - Rocky Kolb (University of Chicago): The Quantum and the Cosmos (public lecture)
2014-08-15 14:00 in P8445B - Dmitri Pogosyan (University of Alberta): Topology of the Universe from Planck CMB data

[ See complete seminar archives | iCal feed ]


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