RESEARCH AND PUBLICATIONS
My main research interests are classical and quantum gravity, black hole physics, fundamental structure of spacetime, and classical and quantum cosmology.
K. Blanchette, S. Das, S. Hergott, S. Rastgoo, Black hole singularity resolution via the modified Raychaudhuri equation in Loop Quantum Gravity, 2020, arXiv:2011.11815 [gr-qc].
R. Gambini, S. Rastgoo, J. Pullin, Gravitation in terms of observables 2: the algebra of fundamental observables, Class. Quantum Grav. 37 145013 (2020), arXiv:2003.01589 [gr-qc].
H. A. Morales-Técotl, S. Rastgoo, J. C. Ruelas, Effective dynamics of the Schwarzschild black hole interior with inverse triad corrections, 2018, arXiv:1806.05795 [gr-qc].
Y. Bonder, A. Garcia-Chung, S. Rastgoo, Bounds on the Polymer Scale from Gamma Ray Bursts, Phys. Rev. D 96, 106021 (2017), arXiv:1704.08750 [gr-qc].
A. Corichi, J. Olmedo, S. Rastgoo, Callan-Giddings-Harvey-Strominger vacuum in loop quantum gravity and singularity resolution, Phys. Rev. D 94, 084050 (2016), arXiv:1608.06246 [gr-qc].
S. Rastgoo, M. Requardt, Emergent Space-Time via a Geometric Renormalization Method, Phys. Rev. D. 94, 124019 (2016), arXiv:1606.08073 [gr-qc].
R. Gambini, J. Pullin, S. Rastgoo, Small Lorentz violations in quantum gravity: do they lead to unacceptably large effects?, Class. Quantum Grav. 28 155005 (2011), arXiv:1106.1417 [gr-qc].
R. Gambini, J. Pullin and S. Rastgoo, Quantum scalar field in quantum gravity: the vacuum in the spherically symmetric case, Class. Quantum Grav. 26 215011 (2009), arXiv:0906.1774 [gr-qc].
Classical and Quantum Black Holes
Black holes are one of the main playgrounds of quantum gravity. The objectives of this project is to the study these objects in quantum and semiclassical regimes, as well as obtaining crucial hints about quantum gravity in general from studying their behavior.
Part of this project includes investigating about the behavior of the interior of quantum black holes, particularly close or at their classical singularity, where quantum gravity effects are important. Another part is the study of the propagation and backreaction of quantum matter on (quantum) spacetimes of black holes, in order to find important observable effects in the exterior of black holes.
Quantum Gravity Fundamentals / Structure and Emergence of Spacetime
In this project, my goal is understanding the fine structure underlying the classical spacetime, by considering the latter an emergent phenomenon. This similar to the situation in thermodynamics or fluid mechanics where a continuous liquid or a gas in fact consists of a very large number of atoms, and the behavior of these atoms results in emergent concepts such as pressure and temperature.
Here I work on various bottom-up and top-down approaches to quantum gravity, in order to develop a novel model of the structure underlying spacetime, and the mechanism of spacetime emergence.
This project is pursued in collaboration with Prof. Manfred Requardt of Göttingen University.
Quantum Gravity Phenomenology
This project involves deriving viable signatures of quantum gravity from theory, by studying various phenomena, particularly of astrophysical nature, such as Gamma Ray Bursts (GRBs) and Gravitational waves. I am looking for such signatures that can be observed in current or near future experiments.
Certain examples are possible observable modifications to the Feynman propagator of the matter fields, or violation of Lorentz invariance due to quantum structure of spacetime which would lead to, for example, the dependence of the speed of the propagation of light on its frequency. These can possibly be observed in the radiations coming from GRBs. Such effects may also be detectable in gravitational waves in certain conditions.