Publications (61)
The frequency of window damage caused by bolide airbursts: a quarter century case study
Nayeob Gi, Peter Brown, Michael Aftosmis
We have empirically estimated how often fireball shocks produce overpressure at the ground sufficient to damage windows. Our study used a numerical entry model to estimate the ener…
Catastrophic disruption of asteroid 2023 CX1 and implications for planetary defense
Auriane Egal, Denis Vida, François Colas +94
Mitigation of the threat from airbursting asteroids requires an understanding of the potential risk they pose for the ground. How asteroids release their kinetic energy in the atmo…
The He-rich core-collapse supernova 2007Y: Observations from X-ray to Radio Wavelengths
Maximilian Stritzinger, Paolo Mazzali, Mark M. Phillips +21
A detailed study spanning approximately a year has been conducted on the Type Ib supernova 2007Y. Imaging was obtained from X-ray to radio wavelengths, and a comprehensive set of m…
Chain rules for conditional entropies in quantum cryptography: limitations and improvements
Lewis Wooltorton, Peter Brown, Omar Fawzi
Security proofs in quantum cryptography rely on conditional entropies. In a many-round protocol, their estimation is a challenging task; one must account for the most general attac…
Computing conditional entropies for quantum correlations
Peter Brown, Hamza Fawzi, Omar Fawzi
The rates of quantum cryptographic protocols are usually expressed in terms of a conditional entropy minimized over a certain set of quantum states. In particular, in the device-in…
The expanding light echoes from supernova 2014J in M82
Yi Yang, Lifan Wang, Dietrich Baade +10
We present the measurement of the size and surface brightness of the expanding light echoes from supernova (SN) 2014J in the nearby starburst galaxy M82. Hubble Space Telescope (HS…
A Comparison of Fireball Luminous Efficiency Models using Acoustic Records
Luke McFadden, Peter Brown, Denis Vida
The total energy of a fireball is commonly obtained from optical measurements with an assumed value for luminous efficiency. Acoustic energy measurements offer an independent means…
The Carnegie Supernova Project-I: Correlation Between Type Ia Supernovae and Their Host Galaxies from Optical to Near-Infrared Bands
Syed A. Uddin, Christopher R. Burns, M. M. Phillips +13
We present optical and near-infrared () photometry of host galaxies of Type Ia supernovae (SN~Ia) observed by the \textit{Carnegie Supernova Project-I}. We determine host…
Bounds on Petz-Rényi Divergences and their Applications for Device-Independent Cryptography
Thomas A. Hahn, Ernest Y. -Z. Tan, Peter Brown
Variational techniques have been recently developed to find tighter bounds on the von Neumann entropy in a completely device-independent (DI) setting. This, in turn, has led to sig…
An Upper Limit on the Interstellar Meteoroid Flux at Video Sizes from the Global Meteor Network
Paul Wiegert, Vanessa Tran, Cole Gregg +2
Material arriving at our solar system from the Galaxy may be detected at Earth in the form of meteors ablating in our atmosphere. Here we report on a search for interstellar meteor…
A Superluminous Supernova Lightened by Collisions with Pulsational Pair-instability Shells
Weili Lin, Xiaofeng Wang, Lin Yan +23
Superluminous supernovae are among the most energetic stellar explosions in the Universe, but their energy sources remain an open question. Here we present long-term observations o…
CAMO-S: A meteor-tracking spectrograph at the Canadian Automated Meteor Observatory
Michael Mazur, Margaret Campbell-Brown, Peter Brown +3
The Canadian Automated Meteor Observatory (CAMO) mirror tracking system has been in operation since 2009 and has, to date, produced more than 20,000 two-station meteor observations…
Double-offset Cassegrain telescopes for the Ultraviolet Type Ia (UVIa) mission concept
Fernando Cruz Aguirre, Keri Hoadley, Curtis McCully +13
Our understanding of cosmology is shaped by Type Ia supernovae (SNe Ia), the runaway thermonuclear detonations of white dwarfs via accretion from a companion star. The nature of th…
SN 2021csp -- the explosion of a stripped envelope star within a H and He-poor circumstellar medium
Morgan Fraser, Maximilian D. Stritzinger, Sean J. Brennan +48
We present observations of SN 2021csp, a unique supernova (SN) which displays evidence for interaction with H- and He- poor circumstellar material (CSM) at early times. Using high-…
Detecting Earth's Temporarily-Captured Natural Satellites - Minimoons
Bryce Bolin, Robert Jedicke, Mikael Granvik +7
We present a study on the discoverability of temporarily captured orbiters (TCOs) by present day or near-term anticipated ground-based and space-based facilities. TCOs (Granvik et…
Semidefinite programming relaxations for quantum correlations
Armin Tavakoli, Alejandro Pozas-Kerstjens, Peter Brown +1
Semidefinite programs are convex optimisation problems involving a linear objective function and a domain of positive semidefinite matrices. Over the last two decades, they have be…
Simultaneous Optical and Meteor Head Echo measurements using the Middle Atmosphere Alomar Radar System (MAARSY): Data collection and preliminary analysis
Peter Brown, Gunter Stober, Carsten Schult +3
The initial results of a two year simultaneous optical-radar meteor campaign are described. Analysis of 105 double-station optical meteors having plane of sky intersection angles g…
The Dynamical Origin of Millimetre-Sized Sporadic Meteoroids
Tam Do, Peter Brown, Petr Pokorný
Determining the relative contributions of cometary and asteroidal sources to the sporadic meteoroid population remains a longstanding challenge, particularly because commonly used…
Quantifying the Bulk Density of Southern Delta Aquariid Meteoroids: Insights from the Canadian Automated Meteor Observatory
Arazi Pinhas, Zbyszek Krzeminski, Denis Vida +1
Physical properties of ten millimeter-sized meteoroids from the Southern Delta Aquariids (SDA) shower are derived using optical observations from the Canadian Automated Meteor Obse…
Small Near-Earth Asteroids as a Source of Meteorites
JiÅà BoroviÄka, Pavel Spurný, Peter Brown
Small asteroids intersecting Earth's orbit can deliver extraterrestrial rocks to the Earth, called meteorites. This process is accompanied by a luminous phenomena in the atmosphere…
The Potential Danger to Satellites due to Ejecta from a 2032 Lunar Impact by Asteroid 2024 YR4
Paul Wiegert, Peter Brown, Jack Lopes +1
On 2032 December 22 the 60 m diameter asteroid 2024 YR4 has a 4% chance of impacting the Moon. Such an impact would release 6.5 MT TNT equivalent energy and produce a ~1 km diamete…
Device-independent quantum key distribution with arbitrarily small nonlocality
Lewis Wooltorton, Peter Brown, Roger Colbeck
Device-independent quantum key distribution (DIQKD) allows two users to set up shared cryptographic key without the need to trust the quantum devices used. Doing so requires nonloc…
Hybrid Quantum Cryptography from Communication Complexity
Francesco Mazzoncini, Balthazar Bauer, Peter Brown +1
We introduce an explicit construction for a key distribution protocol in the Quantum Computational Timelock (QCT) security model, where one assumes that computationally secure encr…
Possible Interstellar meteoroids detected by the Canadian Meteor Orbit Radar
Mark Froncisz, Peter Brown, Robert J. Weryk
We examine meteoroid orbits recorded by the Canadian Meteor Orbit Radar (CMOR) from 2012-2019, consisting of just over 11 million orbits in a search for potential interstellar mete…
A Low-Mass Helium Star Progenitor Model for the Type Ibn SN 2020nxt
Qinan Wang, Anika Goel, Luc Dessart +55
A growing number of supernovae (SNe) are now known to exhibit evidence for significant interaction with a dense, pre-existing, circumstellar medium (CSM). SNe Ibn comprise one such…
Precision measurements of radar transverse scattering speeds from meteor phase characteristics
Michael Mazur, Petr Pokorny, Peter Brown +5
We describe an improved technique for using the backscattered phase from meteor radar echo measurements just prior to the specular point () to calculate meteor speeds and th…
Pipeline for the Detection of Serendipitous Stellar Occultations by Kuiper Belt Objects with the Colibri Fast-Photometry Array
Emily Pass, Stanimir Metchev, Peter Brown +1
We report results from the preliminary trials of Colibri, a dedicated fast-photometry array for the detection of small Kuiper belt objects through serendipitous stellar occultation…
Provably Optimal Parallel Transport Sweeps on Semi-Structured Grids
Michael P. Adams, Marvin L. Adams, W. Daryl Hawkins +7
We have found provably optimal algorithms for full-domain discrete-ordinate transport sweeps on a class of grids in 2D and 3D Cartesian geometry that are regular at a coarse level…
Device-independent lower bounds on the conditional von Neumann entropy
Peter Brown, Hamza Fawzi, Omar Fawzi
The rates of several device-independent (DI) protocols, including quantum key-distribution (QKD) and randomness expansion (RE), can be computed via an optimization of the condition…
Exact distinguishability between real-valued and complex-valued Haar random quantum states
Tristan Nemoz, Romain Alléaume, Peter Brown
Haar random states are fundamental objects in quantum information theory and quantum computing. We study the density matrix resulting from sampling copies of a -dimensional…
Convergence rates of Sum-of-Hermitian-Squares Hierarchies for the Pauli algebra
Ali Almasi, Dávid Bugár, Cambyse Rouzé +1
Moment/Sum-of-Hermitian-Squares relaxations for noncommutative polynomial optimization problems have become an important tool for analyzing problems within quantum theory. Despite…
Genuine multipartite entanglement is not necessary for standard device-independent conference key agreement
Lewis Wooltorton, Peter Brown, Roger Colbeck
Conference key agreement aims to establish shared, private randomness among many separated parties in a network. Device-independent conference key agreement (DICKA) is a variant in…
Fireball characteristics derivable from acoustic data
Luke McFadden, Peter Brown, Denis Vida +1
Near field acoustical signals from fireballs (ranges<200 km), when detected by dense ground networks, may be used to estimate the orientation of the trajectory of a fireball (Pujol…
Supercatastrophic disruption of asteroids in the context of SOHO comet, fireball and meteor observations
Paul Wiegert, Peter Brown, Petr Pokorný +5
Granvik et al. (2016) report an absence of asteroids on orbits with perihelia near the Sun that they attribute to the 'supercatastrophic disruption' of these bodies. Here we invest…
Expanding bipartite Bell inequalities for maximum multi-partite randomness
Lewis Wooltorton, Peter Brown, Roger Colbeck
Nonlocal tests on multi-partite quantum correlations form the basis of protocols that certify randomness in a device-independent (DI) way. Such correlations admit a rich structure,…
Early Blue Excess from the Type Ia Supernova 2017cbv and Implications for Its Progenitor
Griffin Hosseinzadeh, David J. Sand, Stefano Valenti +11
We present very early, high-cadence photometric observations of the nearby Type Ia SN 2017cbv. The light curve is unique in that it has a blue bump during the first five days of ob…
Explicit asymptotic secret key rate of continuous-variable quantum key distribution with an arbitrary modulation
Aurélie Denys, Peter Brown, Anthony Leverrier
We establish an analytical lower bound on the asymptotic secret key rate of continuous-variable quantum key distribution with an arbitrary modulation of coherent states. Previously…
SN 2023zcu: A Type IIP SN with Early Flash Features
Monalisa Dubey, Kuntal Misra, Géza Csörnyei +51
We present a detailed photometric and spectroscopic analysis of the Type IIP supernova SN~2023zcu, which exploded in the galaxy NGC~2139 (redshift = 0.006). SN~2023zcu exhibits…
Observations of the Very Young Type Ia Supernova 2019np with Early-excess Emission
Hanna Sai, Xiaofeng Wang, Nancy Elias-Rosa +30
Early-time radiative signals from type Ia supernovae (SNe Ia) can provide important constraints on the explosion mechanism and the progenitor system. We present observations and an…
Determining the population of Large Meteoroids in Major Meteor Showers
Kasia Wisniewski, Peter Brown, Danielle Moser +1
We have estimated the largest meteoroids present in major meteor showers from observations conducted between 2019-2022 by the Geostationary Lightning Mapper (GLM) instrument on the…
Tight analytic bound on the trade-off between device-independent randomness and nonlocality
Lewis Wooltorton, Peter Brown, Roger Colbeck
Two parties sharing entangled quantum systems can generate correlations that cannot be produced using only shared classical resources. These nonlocal correlations are a fundamental…
SN 2013aa and SN 2017cbv: Two Sibling Type Ia Supernovae in the spiral galaxy NGC 5643
Christopher R Burns, Chris Ashall, Carlos Contreras +26
We present photometric and spectroscopic observations of SN 2013aa and SN 2017cbv, two nearly identical type Ia supernovae (SNe Ia) in the host galaxy NGC 5643. The optical photome…
Swift Observations of GRB 050603: An afterglow with a steep late time decay slope
Dirk Grupe, Peter Brown, Jay Cummings +16
We report the results of Swift observations of the Gamma Ray Burst GRB 050603. With a V magnitude V=18.2 about 10 hours after the burst the optical afterglow was the brightest so f…
The Sariçiçek howardite fall in Turkey: Source crater of HED meteorites on Vesta and impact risk of Vestoids
Ozan Unsalan, Peter Jenniskens, Qing-Zhu Yin +76
The Sariçiçek howardite meteorite shower consisting of 343 documented stones occurred on 2 September 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotope…
Meteor Shower Detection with Density-Based Clustering
Glenn Sugar, Althea Moorhead, Peter Brown +1
We present a new method to detect meteor showers using the Density-Based Spatial Clustering of Applications with Noise algorithm (DBSCAN; Ester et al. 1996). DBSCAN is a modern clu…
Impact detections of temporarily captured natural satellites
David L. Clark, Pavel Spurný, Paul Wiegert +4
Temporarily Captured Orbiters (TCOs) are Near-Earth Objects (NEOs) which make a few orbits of Earth before returning to heliocentric orbits. Only one TCO has been observed to date,…
Analytic Rényi Entropy Bounds for Device-Independent Cryptography
Thomas A. Hahn, Aby Philip, Ernest Y. -Z. Tan +1
Device-independent (DI) cryptography represents the highest level of security, enabling cryptographic primitives to be executed safely on uncharacterized devices. Moreover, with su…
On the age and formation mechanism of the core of the Quadrantid meteoroid stream
Abedin Abedin, Pavel Spurny, Paul Wiegert +3
The Quadrantid meteor shower is among the strongest annual meteor showers, and has drawn the attention of scientists for several decades. The stream is unusual, among others, for s…
Faint NUV/FUV Standards from Swift/UVOT, GALEX and SDSS Photometry
Michael H. Siegel, Erik A. Hoversten, Peter W. A. Roming +8
At present, the precision of deep ultraviolet photometry is somewhat limited by the dearth of faint ultraviolet standard stars. In an effort to improve this situation, we present a…
Cosmology with Photometrically-Classified Type Ia Supernovae from the SDSS-II Supernova Survey
Heather Campbell, Chris B. D'Andrea, Robert C. Nichol +25
We present the cosmological analysis of 752 photometrically-classified Type Ia Supernovae (SNe Ia) obtained from the full Sloan Digital Sky Survey II (SDSS-II) Supernova (SN) Surve…
Coordinated Optical and Radar Measurements of Low Velocity Meteors
Peter Brown, Robert J. Weryk
To better estimate which luminous efficiency () value is compatible with contemporary values of the ionization coefficient (), we report a series of simultaneous optical an…
Catching Element Formation In The Act
Chris L. Fryer, Frank Timmes, Aimee L. Hungerford +216
Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects…
Refinement of Bolide Characteristics from Infrasound measurements
Nayeob Gi, Peter Brown
We have detected and performed signal measurements on 78 individual bolide events as recorded at 179 infrasound stations between 2006 and 2015. We compared period-yield relations w…
Triple Halide Wide Bandgap Perovskites for Efficient Indoor Photovoltaics
Shaoyang Wang, Paul R. Edwards, Maged Abdelsamie +10
Indoor photovoltaics are receiving tremendous attention due to the continuous development of the Internet of Things (IoT). Here we report a triple anion (TA) perovskite CH3NH3PbI2.…
Space-time reduced order model for large-scale linear dynamical systems with application to Boltzmann transport problems
Youngsoo Choi, Peter Brown, Bill Arrighi +1
A classical reduced order model for dynamical problems involves spatial reduction of the problem size. However, temporal reduction accompanied by the spatial reduction can further…
Radiative Transfer Modeling of An SN 1987A Light EchoAT2019xis
Jiachen Ding, Lifan Wang, Peter Brown +1
We use a Monte Carlo radiative transfer model (MCRTM) to simulate the UBVRI light curves, images and linear polarization of a light echo from supernova SN1987A in the Large Mage…
Identification of meteorite source regions in the Solar System
Mikael Granvik, Peter Brown
Over the past decade there has been a large increase in the number of automated camera networks that monitor the sky for fireballs. One of the goals of these networks is to provide…
The impact and recovery of asteroid 2018 LA
Peter Jenniskens, Mohutsiwa Gabadirwe, Qing-Zhu Yin +63
The June 2, 2018, impact of asteroid 2018 LA over Botswana is only the second asteroid detected in space prior to impacting over land. Here, we report on the successful recovery of…
Observations of SN 2017ein Reveal Shock Breakout Emission and A Massive Progenitor Star for a Type Ic Supernova
Danfeng Xiang, Xiaofeng Wang, Jun Mo +23
We present optical and ultraviolet observations of nearby type Ic supernova SN 2017ein as well as detailed analysis of its progenitor properties from both the early-time observatio…
Measuring the meteoroid environments of the planets with meteor detectors on Earth
Paul Wiegert, Peter Brown, Petr Pokorny +2
We describe how meteors recorded at the Earth can be used to partly reconstruct the meteoroid environments of the planets if a large sample (i.e. millions of orbits at a minimum) i…
How much secure randomness is in a quantum state?
Kriss Gutierrez Anco, Tristan Nemoz, Peter Brown
How much cryptographically-secure randomness can be extracted from a quantum state? This fundamental question probes the absolute limits of quantum random number generation (QRNG)…