133 citations · 487 across the 18 of their papers we have counts for
19 papers
WIMPs with Enhanced Annihilation from a Feebly Interacting Unstable Partner
Chance Hoskinson, Pearl Sandick, Barmak Shams Es Haghi
Weakly interacting massive particles (WIMPs) constitute one of the best-motivated dark matter (DM) candidates. In this study, we consider a simple extension of the WIMP paradigm in…
Phenomenology of Inflaton-Driven Early QCD Confinement and Solution to Axion Isocurvature Problem
Evangelos I. Sfakianakis, Barmak Shams Es Haghi, Katherine Freese
We study the phenomenology of early QCD confinement during inflation, driven by a direct coupling between the inflaton and Standard Model gluons. This coupling dynamically raises t…
Isocurvature-Free QCD Axion Dark Matter from Inflaton-Driven Early QCD: the Necessity of Inflationary Plateaus
Katherine Freese, Evangelos I. Sfakianakis, Barmak Shams Es Haghi
A direct coupling between the inflaton and Standard Model gluons can dynamically raise the QCD confinement scale during inflation, making the axion temporarily heavy and suppressin…
Probing High Reheating Temperatures by Direct Detection Experiments
Barmak Shams Es Haghi
We argue that the benchmark freeze in dark matter (DM) scenario for direct detection experiments, in which a DM candidate interacts with the Standard Model (SM) through an ultralig…
Thermal Gravitons from Warm Inflation
Gabriele Montefalcone, Barmak Shams Es Haghi, Tao Xu +1
In warm inflation (WI), the persistent thermal bath that is sustained by dissipative interactions with the inflaton field produces a stochastic background of gravitational waves (G…
Setting up stasis with gravitational interactions
Andrew J. Long, Barmak Shams Es Haghi, Moira Venegas
An epoch known as cosmological stasis may have taken place in the early Universe. During matter-radiation stasis, a population of non-relativistic particles with different masses g…
Indirect Detection of Hot Dark Matter
Jeff A. Dror, Pearl Sandick, Barmak Shams Es Haghi +1
Cosmologically stable, light particles that came into thermal contact with the Standard Model in the early universe may persist today as a form of hot dark matter. For relics with…
Conversations and Deliberations: Non-Standard Cosmological Epochs and Expansion Histories
Brian Batell, Keith R. Dienes, Brooks Thomas +17
This document summarizes the discussions which took place during the PITT-PACC Workshop entitled "Non-Standard Cosmological Epochs and Expansion Histories," held in Pittsburgh, Pen…
Dark Matter production during Warm Inflation via Freeze-In
Katherine Freese, Gabriele Montefalcone, Barmak Shams Es Haghi
We present a novel perspective on the role of inflation in the production of Dark Matter (DM). Specifically, we explore the DM production during Warm Inflation via ultraviolet Free…
Recycled Dark Matter
Thomas C. Gehrman, Barmak Shams Es Haghi, Kuver Sinha +1
We outline a new production mechanism for dark matter that we dub "recycling": dark sector particles are kinematically trapped in the false vacuum during a dark phase transition; t…
Baryogenesis and Primordial Black Hole Dark Matter from Heavy Metastable Particles
Barmak Shams Es Haghi
We propose a novel and simple scenario to explain baryon asymmetry and dark matter (DM) by utilizing an early matter-dominated era (EMDE) caused by a heavy metastable particle. Wit…
Detection of Early-Universe Gravitational Wave Signatures and Fundamental Physics
Robert Caldwell, Yanou Cui, Huai-Ke Guo +34
Detection of a gravitational-wave signal of non-astrophysical origin would be a landmark discovery, potentially providing a significant clue to some of our most basic, big-picture…
Dark radiation constraints on light primordial black holes
Jérémy Auffinger, Alexandre Arbey, Pearl Sandick +2
Light black holes could have formed in the very early universe through the collapse of large primordial density fluctuations. These primordial black holes (PBHs), if light enough,…
Gravitational Waves from Mini-Split SUSY
Bartosz Fornal, Barmak Shams Es Haghi, Jiang-Hao Yu +1
We show that color-breaking vacua may develop at high temperature in the Mini-Split Supersymmetry (SUSY) scenario. This can lead to a nontrivial cosmological history of the Univers…
The Effects of Primordial Black Holes on Dark Matter Models
Paolo Gondolo, Pearl Sandick, Barmak Shams Es Haghi
We investigate the effects of producing dark matter by Hawking evaporation of primordial black holes (PBHs) in scenarios that may have a second well-motivated dark matter productio…
MADHAT: Model-Agnostic Dark Halo Analysis Tool
Kimberly K. Boddy, Stephen Hill, Jason Kumar +2
We present the Model-Agnostic Dark Halo Analysis Tool (MADHAT), a numerical tool which implements a Fermi-LAT data-driven, model-independent analysis of gamma-ray emission from dwa…
SUSY Signals from QCD Production at the Upgraded LHC
Tao Han, Ahmed Ismail, Barmak Shams Es Haghi
Weak-scale supersymmetry remains to be one of the best-motivated theories of physics beyond the Standard Model. We evaluate the sensitivities of the High Luminosity (HL) and High E…
Thermal Dark Matter Through the Dirac Neutrino Portal
Brian Batell, Tao Han, David McKeen +1
We study a simple model of thermal dark matter annihilating to standard model neutrinos via the neutrino portal. A (pseudo-)Dirac sterile neutrino serves as a mediator between the…
Indirect Detection of Neutrino Portal Dark Matter
Brian Batell, Tao Han, Barmak Shams Es Haghi
We investigate the feasibility of the indirect detection of dark matter in a simple model using the neutrino portal. The model is very economical, with right-handed neutrinos gener…