25 citations · 104 across the 15 of their papers we have counts for
16 papers
Matter Maps to Geometry in Gravitational Collapse
H. Khodabakhshi, Zhi-Chao Li, H. Lu +1
We establish an exact bidirectional map between the effective homogeneous interior density of a collapsing star and the exterior metric function in generalized Oppenheimer--Snyder…
Classification of Oppenheimer-Snyder Collapse: Singular, Bouncing, and Soft-Landing Scenarios
Zhi-Chao Li, H. Khodabakhshi, H. Lu
We study Oppenheimer-Snyder (OS) gravitational collapse matched to a general static, spherically symmetric exterior spacetime. Unlike the Schwarzschild case, two new features can a…
The Upper Bound of Event Horizon Formation Time in Generalized Oppenheimer-Snyder Collapse
Zhi-Chao Li, H. Khodabakhshi, H. Lu
We prove that, in the framework of the Oppenheimer-Snyder collapse, the Schwarzschild exterior maximizes the event horizon formation time among all a…
Gravitational Collapse: Generalizing Oppenheimer-Snyder and a Conjecture on Horizon Formation Time
H. Khodabakhshi, H. Lu, F. Shojai
We generalize the Oppenheimer-Snyder model of gravitational collapse by considering a broader class of static, spherically symmetric exterior spacetimes, with an interior geometry…
Weak Cosmic Censorship Conjecture Cannot be Violated in Gedanken Experiments
Peng-Yu Wu, H. Khodabakhshi, H. Lu
We innovate a systematic investigation of the Weak Cosmic Censorship Conjecture (WCCC) using gedanken experiments involving black hole perturbations by test particles. We classify…
Cosmology with Higher-Derivative Gravities
H. Khodabakhshi, M. Farhang, F. Shojai +1
We introduce an ingenious approach to explore cosmological implications of higher-derivative gravity theories. The key novelty lies in the characterization of the additional massiv…
Observational Feasibility of 4D Einstein-Gauss-Bonnet Cosmology: Bouncing and Non-Bouncing Universes
H. Khodabakhshi, M. Farhang, H. Lü
This paper analyzes the possibility of bouncing and non-bouncing universes in the framework of four-dimensional Einstein-Gauss-Bonnet (4D-EGB) gravity, corresponding respectively t…
Cosmological Time Crystals from Gauss-Bonnet Gravity in Four Dimensions
H. Khodabakhshi, F. Shojai, H. Lü
We investigate various cosmological aspects of a 4-Dimensional Gauss-Bonnet Lagrangian, which is integrated into the Einstein Lagrangian with an arbitrary sign, using the Friedman-…
On the Lagrangian Holographic Relation at and Limits of Gravity
H. Khodabakhshi, H. Lu, R. B. Mann
The gravitational Lagrangian can be written as a summation of a bulk and a total derivative term. For some theories of gravity such as Einstein gravity, or more general Lovelock gr…
Tightening the Penrose Inequality
H. Khodabakhshi, H. Lu, Run-Qiu Yang
The Penrose inequality estimates the lower bound of the mass of a black hole in terms of the area of its horizon. This bound is relatively loose for extremal or near extremal black…
Classical Holographic Relations and Alternative Boundary Conditions for Lovelock Gravity
H. Khodabakhshi, H. Lu
We obtain the classical holographic relation for the general Lovelock gravity and decompose the full Lagrangian into the bulk term and the surface term, expressed as a total deriva…
Understanding and Improving Artifact Sharing in Software Engineering Research
Christopher S. Timperley, Lauren Herckis, Claire Le Goues +1
In recent years, many software engineering researchers have begun to include artifacts alongside their research papers. Ideally, artifacts, including tools, benchmarks, and data, s…
Gravitational Lensing by Black Holes in Einstein Quartic Gravity
H. Khodabakhshi, Robert B. Mann
We investigate gravitational lensing effects of spherically symmetric black holes in Einstein Quartic Gravity (EQG). Using an approximate analytic solution obtained by continued fr…
Einstein Quartic Gravity: Shadows, Signals, and Stability
H. Khodabakhshi, A. Giaimo, Robert B. Mann
Using a continued fraction ansatz we obtain an analytic approximation for a spherically symmetric black hole solution to Einsteinian Quartic Gravity (EQG), the next simplest Genera…
Black Hole Entropy and Boundary Conditions
H. Khodabakhshi, A. Shirzad, F. Shojai +1
It is well-known that in order to make the action well defined, one may employ different kinds of boundary conditions (BCs) accompanied by the appropriate Gibbons-Hawking-York (GHY…
On the classification of consistent boundary conditions for -Gravity
H. Khodabakhshi, F. Shojai, A. Shirzad
Using a completely covariant approach, we discuss the role of boundary conditions (BCs) and the corresponding Gibbons--Hawking--York (GHY) terms in -gravi…