283 citations · 1.4k across the 45 of their papers we have counts for
45 papers
A No-Go Theorem for the Mass-Radius Relation of Solitons
Mohammad Hossein Namjoo
We prove a no-go theorem for the mass-radius relation of localized and stable field configurations, known as solitons. Defining the mass-radius index by $Γ\equiv \frac{\rm{d}\ln M}…
Statistical isotropy of the universe and the look-elsewhere effect
Alan H. Guth, Mohammad Hossein Namjoo
Recently, Jones et al. [arXiv:2310.12859] claimed strong evidence for the statistical anisotropy of the universe. The claim is based on a joint analysis of four different anomaly t…
Probabilistic inference in very large universes
Feraz Azhar, Alan H. Guth, Mohammad Hossein Namjoo
[Abridged] Some cosmological theories propose that the observable universe is a small part of a much larger universe in which parameters describing the low-energy laws of physics v…
Geometry of non-Gaussianity in transient non-attractor inflation
Mohammad Hossein Namjoo, Bahar Nikbakht
Inflationary models predicting abundant primordial black holes (PBHs) and large amplitude of scalar-induced gravitational waves (SIGWs) often rely on amplified fluctuations over li…
Non-relativistic effective theories for fields with general potentials and their implications for cosmology
H. S. Modirzadeh, R. Moti, M. H. Namjoo
Non-relativistic effective field theories (NREFTs) play a crucial role in various areas of physics, from cold atom experiments to cosmology. In this paper, we present a systematic…
Bayesian forecasting with information theory
Mohammad Hossein Namjoo
Forecasting techniques for assessing the power of future experiments to discriminate between theories or discover new laws of nature are of great interest in many areas of science.…
Non-Gaussianity consistency relations and their consequences for the peaks
Mohammad Hossein Namjoo, Bahar Nikbakht
Strong deviations from scale invariance and the appearance of high peaks in the primordial power spectrum have been extensively studied for generating primordial black holes (PBHs)…
One consistency relation for all single-field inflationary models
Mohammad Hossein Namjoo
In this paper, we present a non-Gaussianity consistency relation that enables the calculation of the squeezed limit bispectrum of the curvature perturbation in single-field inflati…
Bayesian questions with frequentist answers
Alan H. Guth, Mohammad Hossein Namjoo
The two statistical methods, namely the frequentist and the Bayesian methods, are both commonly used for probabilistic inference in many scientific situations. However, it is not s…
Tail diversity from inflation
Sina Hooshangi, Mohammad Hossein Namjoo, Mahdiyar Noorbala
The tail of the distribution of primordial fluctuations (corresponding to the likelihood of realization of large fluctuations) is of interest, from both theoretical and observation…
Multiple Field Ultra Slow Roll Inflation: Primordial Black Holes From Straight Bulk And Distorted Boundary
Sina Hooshangi, Alireza Talebian, Mohammad Hossein Namjoo +1
We study a model of two-field ultra-slow-roll (USR) inflation bounded by a curve in the field space. Curvature perturbations and non-Gaussianities can be enhanced both during the U…
Rare Events Are Nonperturbative: Primordial Black Holes From Heavy-Tailed Distributions
Sina Hooshangi, Mohammad Hossein Namjoo, Mahdiyar Noorbala
In recent years it has been noted that the perturbative treatment of the statistics of fluctuations may fail to make correct predictions for the abundance of primordial black holes…
Beyond Schrödinger-Poisson: Nonrelativistic Effective Field Theory for Scalar Dark Matter
Borna Salehian, Hong-Yi Zhang, Mustafa A. Amin +2
Massive scalar fields provide excellent dark matter candidates, whose dynamics are often explored analytically and numerically using nonrelativistic Schrödinger-Poisson (SP) equati…
A Bayesian View on the Dr. Evil Scenario
Feraz Azhar, Alan H. Guth, Mohammad Hossein Namjoo
In "Defeating Dr. Evil with Self-Locating Belief", Adam Elga proposes and defends a principle of indifference for self-locating beliefs: if an individual is confident that his worl…
Spacetime singularities and a novel formulation of indeterminism
Feraz Azhar, Mohammad Hossein Namjoo
Spacetime singularities in general relativity are commonly thought to be problematic, in that they signal a breakdown in the theory. We address the question of how to interpret thi…
Effective theories for a nonrelativistic field in an expanding universe: Induced self-interaction, pressure, sound speed, and viscosity
Borna Salehian, Mohammad Hossein Namjoo, David I. Kaiser
A massive, nonrelativistic scalar field in an expanding spacetime is usually approximated by a pressureless perfect fluid, which leads to the standard conclusion that such a field…
Enhanced n-body annihilation of dark matter and its indirect signatures
Mohammad Hossein Namjoo, Tracy R. Slatyer, Chih-Liang Wu
We examine the possible indirect signatures of dark matter annihilation processes with a non-standard scaling with the dark matter density, and in particular the case where more th…
Can Light Dark Matter Solve the Core-Cusp Problem?
Heling Deng, Mark P. Hertzberg, Mohammad Hossein Namjoo +1
Recently there has been much interest in light dark matter, especially ultra-light axions, as they may provide a solution to the core-cusp problem at the center of galaxies. Since…
Revisiting non-Gaussianity from non-attractor inflation models
Yi-Fu Cai, Xingang Chen, Mohammad Hossein Namjoo +3
Non-attractor inflation is known as the only single field inflationary scenario that can violate non-Gaussianity consistency relation with the Bunch-Davies vacuum state and generat…
Relativistic Corrections to Nonrelativistic Effective Field Theories
Mohammad Hossein Namjoo, Alan H. Guth, David I. Kaiser
In this paper we develop a formalism for studying the nonrelativistic limit of relativistic field theories in a systematic way. By introducing a simple, nonlocal field redefinition…
A Direct Probe of the Evolutionary History of the Primordial Universe
Xingang Chen, Mohammad Hossein Namjoo, Yi Wang
Since Hubble and Lamaitre's discovery of the expanding universe using galaxies till the recent discovery of the accelerating universe using standard candles, direct measurements of…
The Future of Primordial Features with Large-Scale Structure Surveys
Xingang Chen, Cora Dvorkin, Zhiqi Huang +2
Primordial features are one of the most important extensions of the Standard Model of cosmology, providing a wealth of information on the primordial universe, ranging from discrimi…
Probing the Primordial Universe using Massive Fields
Xingang Chen, Mohammad Hossein Namjoo, Yi Wang
Inflation models are numerous. It is extremely difficult, if possible at all, to identify the actual underlying inflation model of our primordial universe. Thus, for the purpose of…
Quantum Primordial Standard Clocks
Xingang Chen, Mohammad Hossein Namjoo, Yi Wang
In this paper, we point out and study a generic type of signals existing in the primordial universe models, which can be used to model-independently distinguish the inflation scena…