44 citations · 368 across the 31 of their papers we have counts for
31 papers
Graph-Reweighted Behavior Cloning with Human Interventions for Precise Robotic Manipulation
Xiaoman Li, Zhiqiang Yang, Jiayu Hu +6
Long-horizon precise manipulation produces mixed-quality data for post-training vision-language-action (VLA) models: even successful demonstrations and intervention-assisted rollou…
Disentangling propagation effects from Fast Radio Burst spectra: An analysis on simulated data
Aishwarya Kumar, Fereshteh Rajabi, Martin Houde
We present a methodology to decouple propagation effects, specifically scattering and dispersion, from the intrinsic spectro-temporal properties of repeating Fast Radio Bursts. Uti…
Fast Population Leakage in Astronomical Masers: Maser Amplification and Transient Superradiance
Vahid Anari, Toktam Rashidi, Fereshteh Rajabi
We use a -type three-level Maxwell--Bloch model to test whether an inverted molecular transition in an astronomical maser source can produce maser amplification or superradiance…
Machine-learning approaches to dispersion measure estimation for fast radio bursts
Hosein Rajabi, Zhejian Liu, Fereshteh Rajabi +1
Fast radio bursts (FRBs) are bright, mostly millisecond-duration transients of extragalactic origin whose emission mechanisms remain unknown. As FRB signals propagate through ioniz…
Relativistic Maxwell-Bloch Equations with Applications to Astrophysics
Ningyan Fang, Victor Botez, Fereshteh Rajabi +1
We derive relativistic Maxwell-Bloch equations for potential applications in astronomical environments, where various radiative processes are known to occur, including the maser ac…
Quantum coherence and the invisible Universe: Subradiance as a dark matter mechanism
Martin Houde, Fereshteh Rajabi, Lamies Sati +1
The origin of dark matter in galactic halos, one of the deepest unsolved problems in astrophysics, may find an unexpected contribution from the quantum mechanics of ordinary atomic…
Spectro-temporal analysis of ultra-fast radio bursts using per-channel arrival times
Mohammed A. Chamma, Victor Pop, Fereshteh Rajabi
Fast radio bursts (FRBs), especially those from repeating sources, exhibit a rich variety of morphologies in their dynamic spectra (or waterfalls). Characterizing these morphologie…
Impact of propagation effects on the spectro-temporal properties of Fast Radio Bursts
Aishwarya Kumar, Fereshteh Rajabi, Martin Houde
We present a mathematical analysis of propagation-induced distortions in the spectro-temporal properties of Fast Radio Bursts (FRBs). Within the Triggered Relativistic Dynamical Mo…
Investigations of 2D ion crystals in a hybrid optical cavity trap for quantum information processing
Zewen Sun, Yi Hong Teoh, Fereshteh Rajabi +1
We numerically investigate a hybrid trapping architecture for 2D ion crystals using static electrode voltages and optical cavity fields for in-plane and out-of-plane confinements,…
Validating the Sub-Burst Slope Law: A Comprehensive Multi-Source Spectro-Temporal Analysis of Repeating Fast Radio Bursts
Katie Brown, Mohammed A. Chamma, Fereshteh Rajabi +3
We conduct a comprehensive spectro-temporal analysis of repeating Fast Radio Bursts (FRBs) utilizing nine distinct sources, the largest sample to date. Our data set includes 175 su…
Variability, flaring and coherence -- the complementarity of the maser and superradiance regimes
Martin Houde, Fereshteh Rajabi, Gordon C. MacLeod +5
We discuss the role that coherence phenomena can have on the intensity variability of spectral lines associated with maser radiation. We do so by introducing the fundamental cooper…
Modelling of the multi-transition periodic flaring in G9.62+0.20E
F. Rajabi, M. Houde, G. C. MacLeod +5
We present detailed modeling of periodic flaring events in the 6.7 GHz and 12.2 GHz methanol lines as well as the OH 1665 MHz and 1667 MHz transitions observed in the G9.62+0.20E s…
A broad survey of spectro-temporal properties from FRB 20121102A
Mohammed A. Chamma, Fereshteh Rajabi, Aishwarya Kumar +1
We survey the spectro-temporal properties of fast radio bursts from FRB 20121102A observed by earlier studies across a wide range of frequencies. We investigate 167 bursts from FRB…
Transient Structure in the Non-linear Superradiance Regime of Widely Doppler Broadened Media
Christopher Wyenberg, Fereshteh Rajabi, Mohammed Chamma +2
We investigate transient radiation processes in the non-linear superradiance (SR) regime of the Doppler broadened Maxwell-Bloch equations when the velocity distribution is of total…
Superradiance from a Relativistic Source
Christopher Wyenberg, Fereshteh Rajabi, Martin Houde
We construct a model of cooperative superradiant emission from a highly relativistic multi-particle source. We revise an existing model of the literature for a relativistic two-lev…
The generation and transformation of polarisation signals in molecular lines through collective anisotropic resonant scattering
Martin Houde, Boy Lankhaar, Fereshteh Rajabi +1
We discuss the existence of elliptical polarisation in rotational spectral lines of CO and other molecules within the context of the Anisotropic Resonant Scattering (ARS) model. We…
Generalisation of the Menegozzi & Lamb Maser Algorithm to the Transient Superradiance Regime
C. M. Wyenberg, B. Lankhaar, F. Rajabi +2
We investigate the application of the conventional quasi-steady state maser modelling algorithm of Menegozzi & Lamb (ML) to the high field transient regime of the one-dimensional M…
Manipulating phonons of a trapped-ion system using optical tweezers
Yi Hong Teoh, Manas Sajjan, Zewen Sun +2
We propose an experimental architecture where an array of optical tweezers affords site-dependent control over the confining potential of a conventional radio-frequency ion trap. T…
Evidence of a shared spectro-temporal law between sources of repeating fast radio bursts
Mohammed A. Chamma, Fereshteh Rajabi, Christopher M. Wyenberg +2
We study the spectro-temporal characteristics of two repeating fast radio bursts (FRBs), namely, FRB 20180916B and FRB 20180814A, and combine the results with those from our earlie…
A simple relationship for the spectro-temporal structure of bursts from FRB 121102
Fereshteh Rajabi, Mohammed A. Chamma, Christopher M. Wyenberg +2
We consider a simple dynamical and relativistic model to explain the spectro-temporal structure often displayed by repeating fast radio bursts (FRBs). We show how this model can ac…
Astronomical masers and Dicke's superradiance
Fereshteh Rajabi, Martin Houde
We consider the radiation properties and processes of a gas with a population inversion using the formalism based on the Maxwell-Bloch equations. We focus on the maser action and D…
Detection of new methanol maser transitions associated with G358.93-0.03
G. C. MacLeod, K. Sugiyama, T. R. Hunter +18
We report the detection of new 12.178, 12.229, 20.347, and 23.121 GHz methanol masers in the massive star-forming region G358.93-0.03, which are flaring on similarly short timescal…
Triggered superradiance and fast radio bursts
Martin Houde, Fereshteh Rajabi, B. M. Gaensler +2
In this paper we develop a model for fast radio bursts (FRBs) based on triggered superradiance (SR) and apply it to previously published data of FRB 110220 and FRB 121102. We show…
New evidence for Dicke's superradiance in the 6.7 GHz methanol spectral line in the interstellar medium
F. Rajabi, M. Houde, A. Bartkiewicz +3
We present new evidence for superradiance in the methanol 6.7 GHz spectral line for three different star-forming regions: S255IR-NIRS3, G24.329+0.144, and Cepheus A. Our analysis s…