Title: Do we have dark matter in modified gravity? 
Speaker: Prof.Murli Manohar Verma (University of Lucknow) 
Time:3:00pm, Nov.20th, 2018 (Tuesday), 2018 
Place: Seminar room 319, Theoretical Physics Division 

Abstract: In this talk, the speaker will discuss the geometrical effects of dark matter without actually invoking the dark matter, per se, in the standard form. It will be done by modifying the Einstein-Hilbert action, especially in f(R) model and the new scalar field would be discussed under a conformal transformation from the Jordan frame to the Einstein frame. The speaker will show that the mass of the scalaron undergoes a chameleon mechanism and becomes large in the high curvature regions to cause a screening of the fifth force. The speaker will also discuss the cosmological conditions on various features of the scalaron to show how it can act as a dark matter particle.