Observational tests of MOdified Gravity (MOG) with rotation curves of dwarf galaxies and cluster Abell 1689 acceleration data

محمّد حسین ژولیده حقیقی (دانشکده فیزیک دانشگاه صنعتی شریف )

به مکان جدید سمینار کیهان شناسی در ترم پاییز 96 توجه فرمایید

Abstract: Modified Gravity (MOG) is one alternative to General Relativity. It is able to explain the rotation curves of spiral galaxies and clusters of galaxies without including dark matter. In the weak-field approximation we have an effective gravitational potential that has two components: (i) Newtonian gravity with the gravitational constant enhanced by a factor (1+\alpha) and (ii) a Yukawa type potential that produces a repulsive force with length scale 1/(\mu). In this work we compare the rotation curves of dwarf galaxies in the LITTLE THINGS catalog with predictions of MOG. We find that the universal parameters of this theory, can fit the rotation curve of dwarf galaxies with a larger stellar mass to the light ratio compared to the nearby stars in the Milky Way galaxy. ( arXiv:1609.07851)

In the second part of my presentation I would to talk about cluster Abell 1689. The galaxy cluster system Abell 1689 has been well studied and yields good lensing and X-ray gas data. Modified gravity (MOG) is applied to the cluster Abell 1689 and the acceleration data is well fitted without assuming dark matter. Newtonian dynamics and Modified Newtonian dynamics (MOND) are shown not to fit the acceleration data, while a dark matter model based on the Navarro-Frenk-White (NFW) mass profile is shown to fit the acceleration data for the radial range r>200kpc. (arXiv:1611.05382)

یکشنبه 16 مهر ماه 1396، ساعت 15:00

دانشکده فیزیک، تالارپرتوی