Academic Portfolio
Title: A study of Quantum Field during the inflationary era and production of Primordial Black Hole
In this study we attempted to build a complete quantum description of the primordial black hole (PBH) formation. By combining quantum field theory in curved space with the horizon quantum mechanics formalism we have managed to achieve that. We have started our work by perturbing the Einstein-Hilbert action using the Arnowitt–Deser–Misner (ADM) formalism and calculated the gauge invariant Mukhanov-Sasaki equation from there. By analyzing the canonically quantizedMukhanov-Sasaki variable, we have demonstrated that the vacuum fluctuations evolve into highly squeezed states. In the superhorizon limits these states exhibit Gaussian statistics, representing a coherent macroscopic source. We present the horizon quantum mechanics formalism, derive the spectral decomposition of the source and its associated horizon wavefunction. By analytically solving the quantum overlap integral between the course and the horizon states, we derive the probability of PBH formation. We demonstrate that for a gaussian source the formation probability varies from zero to unity with the density contrast. This result explicitly recovers the classical "Hoop Conjuncture" and the standard Press-Schechter abundance in the macroscopic limit.
© 2026 Mariem Absar.
Title: Upcoming
đź“„ Internship Report-2026 (PDF)
Abstract: Upcoming
© 2026 Mariem Absar.
Title: A Study on Quintessence: An Alternative to Cosmological Constant
Abstract: This report explores the fundamental challenges of the cosmological constant in a technical level and establishes radiative instability as the main problem with cosmological constant. To address this issue, Quintessence(a dynamic scalar field) is proposed as a candidate for dark energy, responsible for the late-time accelerated expansion of the universe. The report develops a theoretical formulation of a general Quintessence scalar field and examines the cosmological dynamics. A numerical study is done on thawing type of quintessence models and compared with the result of ΛCDM.
© 2026 Mariem Absar.
In this section, I have uploaded my notes prepared while doing the background study of my research project.
đź“„ Cosmological Perturbation Theory (PDF)
© 2026 Mariem Absar.
Hello! I am Mariem Absar, completed my Undergraduate and Master’s in Physics from the University of Chittagong. My research interests include Early Universe Cosmology, Black hole Physics, and Physics Beyond Standard Model. This site showcases my research, internship reports, and academic work.