37 citations · 221 across the 21 of their papers we have counts for
21 papers
Spectral Density of the Causal Propagator
Joshua Y. L. Jones, Yasaman K. Yazdi
The causal propagator (or Pauli-Jordan function), which multiplied by is the spacetime commutator of the field , plays an essential role in scalar quantum field t…
Spectral Spacetime Entropy for Quasifree Theories
Joshua Y. L. Jones, Yasaman K. Yazdi
Motivated by the necessity to UV-regularise entanglement entropy, we present a spectral method for calculating the entropy of quasifree states, for both bosonic and fermionic field…
Fluctuations and Correlations in Causal Set Theory
Heidar Moradi, Yasaman K. Yazdi, Miguel Zilhão
We study the statistical fluctuations (such as the variance) of causal set quantities, with particular focus on the causal set action. To facilitate calculating such fluctuations,…
Aspects of Everpresent (II): Cosmological Tests of Current Models
Santanu Das, Arad Nasiri, Yasaman K. Yazdi
This paper investigates Everpresent , a stochastic dark energy model motivated by causal set theory and unimodular gravity, and confronts it with two key observational data sets…
Aspects of Everpresent (I): A Fluctuating Cosmological Constant from Spacetime Discreteness
Santanu Das, Arad Nasiri, Yasaman K. Yazdi
We provide a comprehensive discussion of the Everpresent cosmological model arising from fundamental principles in causal set theory and unimodular gravity. In this framework t…
Entanglement Entropy and Causal Set Theory
Yasaman K. Yazdi
We review a formulation of the entanglement entropy of a quantum scalar field in terms of its spacetime two-point correlation functions. We discuss applications of this formulation…
On the (Non)Hadamard Property of the SJ State in a D Causal Diamond
Yifeng Rocky Zhu, Yasaman K. Yazdi
The Sorkin-Johnston (SJ) state is a candidate physical vacuum state for a scalar field in a generic curved spacetime. It has the attractive feature that it is covariantly and uniqu…
Insights on Entanglement Entropy in Dimensional Causal Sets
Théo Keseman, Hans J. Muneesamy, Yasaman K. Yazdi
Entanglement entropy in causal sets offers a fundamentally covariant characterisation of quantum field degrees of freedom. A known result in this context is that the degrees of fre…
Entanglement Entropy of Disjoint Spacetime Intervals in Causal Set Theory
Callum F. Duffy, Joshua Y. L. Jones, Yasaman K. Yazdi
A more complete understanding of entanglement entropy in a covariant manner could inform the search for quantum gravity. We build on work in this direction by extending previous re…
Lorentzian Spectral Geometry with Causal Sets
Yasaman K. Yazdi, Marco Letizia, Achim Kempf
We study discrete Lorentzian spectral geometry by investigating to what extent causal sets can be identified through a set of geometric invariants such as spectra. We build on prev…
Entanglement Entropy of Causal Set de Sitter Horizons
Sumati Surya, Nomaan X, Yasaman K. Yazdi
de Sitter cosmological horizons are known to exhibit thermodynamic properties similar to black hole horizons. In this work we study causal set de Sitter horizons, using Sorkin's sp…
Towards Spacetime Entanglement Entropy for Interacting Theories
Yangang Chen, Lucas Hackl, Ravi Kunjwal +3
Entanglement entropy of quantum fields in gravitational settings is a topic of growing importance. This entropy of entanglement is conventionally computed relative to Cauchy hypers…
Studies on the SJ Vacuum in de Sitter Spacetime
Sumati Surya, Nomaan X, Yasaman K. Yazdi
In this work we study the Sorkin-Johnston (SJ) vacuum in de Sitter spacetime for free scalar field theory. For the massless theory we find that the SJ vacuum can neither be obtaine…
Manifold-Topology from K-Causal Order
Rafael D. Sorkin, Yasaman K. Yazdi, Nosiphiwo Zwane
To a significant extent, the metrical and topological properties of spacetime can be described purely order-theoretically. The relation has proven to be useful for this purpo…
Entanglement Entropy in Causal Set Theory
Rafael D. Sorkin, Yasaman K. Yazdi
Entanglement entropy is now widely accepted as having deep connections with quantum gravity. It is therefore desirable to understand it in the context of causal sets, especially si…
Towards Spectral Geometry for Causal Sets
Yasaman K. Yazdi, Achim Kempf
We show that the Feynman propagator (or the d'Alembertian) of a causal set contains the complete information about the causal set. Intuitively, this is because the Feynman propagat…
Accretion in Radiative Equipartition (AiRE) Disks
Yasaman K. Yazdi, Niayesh Afshordi
Standard accretion disk theory (Shakura & Sunyaev 1973) predicts that the total pressure in disks at typical (sub-)Eddington accretion rates becomes radiation pressure dominated. H…
Zero Modes and Entanglement Entropy
Yasaman K. Yazdi
Ultraviolet divergences are widely discussed in studies of entanglement entropy. Also present, but much less understood, are infrared divergences due to zero modes in the field the…
"Firewall" Phenomenology with Astrophysical Neutrinos
Niayesh Afshordi, Yasaman K. Yazdi
One of the most fundamental features of a black hole in general relativity is its event horizon: a boundary from which nothing can escape. There has been a recent surge of interest…
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(…
A Ground State for the Causal Diamond in 2 Dimensions
Niayesh Afshordi, Michel Buck, Fay Dowker +3
We apply a recent proposal for a distinguished ground state of a quantum field in a globally hyperbolic spacetime to the free massless scalar field in a causal diamond in two-dimen…