108 citations · 486 across the 17 of their papers we have counts for
18 papers
Dark matter and nonlocality of spacetime
Mehdi Saravani
In this letter, we review a candidate for dark matter, known as ODM, and explain how it relates to spacetime nonlocality. This connection provides a physical interpretation for…
Classification of shift-symmetric Horndeski theories and hairy black holes
Mehdi Saravani, Thomas P. Sotiriou
No-hair theorems for scalar-tensor theories imply that the trivial scalar field configuration is the unique configuration around stationary black hole spacetimes. The most basic as…
Casimir Effect for Nonlocal Field Theories with Continuum Massive Modes
Mehdi Saravani
In this paper, we study the Casimir force for a class of Lorentzian nonlocal field theories. These theories include a continuum of massive excitations. In this regard, the effect o…
Causal structure of black holes in shift-symmetric Horndeski theories
Robert Benkel, Nicola Franchini, Mehdi Saravani +1
In theories with derivative (self-)interactions, the propagation of perturbations on nontrivial field configurations is determined by effective metrics. Generalized scalar-tensor t…
Continuum Modes of Nonlocal Field Theories
Mehdi Saravani
A class of nonlocal Lorentzian quantum field theories is introduced in arXiv:1502.01655 and arXiv:1411.6513, where the d'Alembertian operator is replaced by a non-analytic f…
Hořava Gravity after GW170817
A. Emir Gumrukcuoglu, Mehdi Saravani, Thomas P. Sotiriou
The recent detection of gravitational wave GW170817 has placed a severe bound on the deviation of the speed of gravitational waves from the speed of light. We explore the consequen…
Black hole horizons at the extremal limit in Lorentz-violating gravity
Nicola Franchini, Mehdi Saravani, Thomas P. Sotiriou
Lorentz-violating gravity theories with a preferred foliation can have instantaneous propagation. Nonetheless, it has been shown that black holes can still exist in such theories a…
Low energy signatures of nonlocal field theories
Alessio Belenchia, Dionigi M. T. Benincasa, Eduardo Martin-Martinez +1
The response of inertial particle detectors coupled to a scalar field satisfying nonlocal dynamics described by nonanalytic functions of the d'Alembertian operator is studie…
Off-shell Dark Matter: A Cosmological relic of Quantum Gravity
Mehdi Saravani, Niayesh Afshordi
We study a novel proposal for the origin of cosmological cold dark matter (CDM) which is rooted in the quantum nature of spacetime. In this model, off-shell modes of quantum fields…
Cosmic Censorship in Lorentz Violating Theories of Gravity
Michael Meiers, Mehdi Saravani, Niayesh Afshordi
Is Cosmic Censorship special to General Relativity, or can it survive a violation of equivalence principle? Recent studies have shown that singularities in Lorentz violating Einste…
Spacetime Curvature in terms of Scalar Field Propagators
Mehdi Saravani, Siavash Aslanbeigi, Achim Kempf
We show how quantum fields can be used to measure the curvature of spacetime. In particular, we find that knowledge of the imprint that spacetime curvature leaves in the correlator…
A Stueckelberg Approach to Quadratic Curvature Gravity and its Decoupling Limits
Kurt Hinterbichler, Mehdi Saravani
Curvature squared terms, when added to the Einstein-Hilbert action and treated non-perturbatively, generically result in the propagation of an extra massive scalar state and an ext…
Dark Matter From Spacetime Nonlocality
Mehdi Saravani, Siavash Aslanbeigi
We propose that dark matter is not yet another new particle in nature, but that it is a remnant of quantum gravitational effects on known fields. We arrive at this possibility in a…
On the Causal Set-Continuum Correspondence
Mehdi Saravani, Siavash Aslanbeigi
We present two results which concern certain aspects of the question: when is a causal set well approximated by a Lorentzian manifold? The first result is a theorem which shows tha…
Generalized Causal Set d'Alembertians
Siavash Aslanbeigi, Mehdi Saravani, Rafael D. Sorkin
We introduce a family of generalized d'Alembertian operators in D-dimensional Minkowski spacetimes which are manifestly Lorentz-invariant, retarded, and non-local, the extent of th…
Spacetime Entanglement Entropy in 1+1 Dimensions
Mehdi Saravani, Rafael D. Sorkin, Yasaman K. Yazdi
arXiv:1205.2953 defines an entropy for a gaussian scalar field in an arbitrary region of either a causal set or a continuous spacetime, given only the correlator $\langleϕ(x)ϕ(…
Dynamical Emergence of Universal Horizons during the formation of Black Holes
Mehdi Saravani, Niayesh Afshordi, Robert B. Mann
Motivations for the existence of a fundamental preferred frame range from pure phenomenology to attempts to solve the non-renormalizability of quantum gravity, the problem of time…
Empty Black Holes, Firewalls, and the Origin of Bekenstein-Hawking Entropy
Mehdi Saravani, Niayesh Afshordi, Robert B. Mann
We propose a novel solution for the endpoint of gravitational collapse, in which spacetime ends (and is orbifolded) at a microscopic distance from black hole event horizons. This m…