Star-UBB Seminar Series:- Compact objects in Weyl geometric gravity
This presentation explores the structural and physical properties of Massachusetts Institute of Technology(MIT) bag model of quark and Bose-Einstein Condensate stars within the framework of conformally invariant Weyl geometric gravity theory. The fundamental theory arises from the simplest conformally invariant action, which is constructed in Weyl geometry using the square of the Weyl scalar, the strength of the Weyl vector and a matter term. The speaker and her team linearize the action with respect to the Weyl scalar by introducing an auxiliary scalar field. They will see that in order to maintain the conformal invariance, they should impose the trace condition on the matter energy-momentum tensor. First, the effects of the Weyl geometry in the evolution of the Universe is reviewed. Then, by adopting a static spherically symmetric interior geometry, the field equations for describing the structure and properties of stellar objects in Weyl geometric gravity are derived and explored. As a general result it turns out that for all the considered equations of state, Weyl geometric gravity stars are more massive than their general relativistic counterparts. As a possible astrophysical application of the obtained results they suggest that the recently observed neutron stars, with masses in the range of 2M⊙ and 3M⊙, could be in fact conformally invariant Weyl geometric neutron or quark stars.
時間:2024.06.13(四) 16:00~17:30
頻道:Zoom ID: 853-7454-4159 ←
講者:Dr. Zahra Haghani دکتر زهرا حقانی (School of Physics, Damghan University, Damghan*, Iran)
語言:英語
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Scientific and Technological Advanced Research- Babeș-Bolyai University(Star-UBB) Seminar Series in Gravitation, Cosmology and Astrophysics
Presently a period of rapid and intense change are being witnessed in our understanding of the gravitational force, at a rate that is quickly increasing since the important observational discoveries of the late 1990s. With the advent of new observational techniques, the emergence of important cosmological and astrophysical paradigms can be seen that lead to a deep change in our understanding of the Universe. Astronomical observations strongly suggest that at large scales the force of gravity may not behave according to standard general relativity, and that a generalization of the gravitational action, either at the geometric level, or at the matter level, may be required for a full understanding of the gravitational interaction.
The goal of the present seminar is to bring Theoretical Gravitational Physics closer to the observations and experiments, and to discuss current topics in general relativity, high-energy physics, astrophysics and cosmology.
此活動由Star-UBB*主辦。