Publications (25)
Signatures of non-gaussianity in the isocurvature modes of primordial black hole dark matter
Sam Young, Christian T. Byrnes
Primordial black holes (PBHs) are black holes which may have formed very early on during the radiation dominated era in the early universe. We present here a method by which the la…
Dark Matter Science in the Era of LSST
Keith Bechtol, Alex Drlica-Wagner, Kevork N. Abazajian +177
Astrophysical observations currently provide the only robust, empirical measurements of dark matter. In the coming decade, astrophysical observations will guide other experimental…
Peaks and primordial black holes: the effect of non-Gaussianity
Sam Young
In light of recent developments in the field, we re-evaluate the effect of local-type non-Gaussianity on the primordial black hole (PBH) abundance (and consequently, upon constrain…
Inflation with two-form field: the production of primordial black holes and gravitational waves
Tomohiro Fujita, Hiromasa Nakatsuka, Ippei Obata +1
Antisymmetric tensor field (two-form field) is a ubiquitous component in string theory and generally couples to the scalar sector through its kinetic term. In this paper, we propos…
The primordial black hole formation criterion re-examined: parameterisation, timing, and the choice of window function
Sam Young
In this paper, the criterion used to determine whether a density perturbation will collapse to form a primordial black hole (PBH) is re-examined, in respect of its use to determine…
The Optical Two and Three-Dimensional Fundamental Plane Correlations for Nearly 180 Gamma-Ray Burst Afterglows with Swift/UVOT, RATIR, and the SUBARU Telescope
Maria Giovanna Dainotti, Sam Young, L. Li +21
Gamma-ray bursts (GRBs) are fascinating events due to their panchromatic nature. We study optical plateaus in GRB afterglows via an extended search into archival data. We comprehen…
Particle Trajectory Representation Learning with Masked Point Modeling
Sam Young, Yeon-jae Jwa, Kazuhiro Terao
Effective self-supervised learning (SSL) techniques have been key to unlocking large datasets for representation learning. While many promising methods have been developed using on…
The long-short wavelength mode coupling tightens primordial black hole constraints
Sam Young, Christian T. Byrnes
The effects of non-gaussianity on the constraints on the primordial curvature perturbation power spectrum from primordial black holes (PBHs) are considered. We extend previous anal…
Initial clustering and the primordial black hole merger rate
Sam Young, Christian T. Byrnes
If the primordial curvature perturbation followed a Gaussian distribution, primordial black holes (PBHs) will be Poisson distributed with no additional clustering. We consider loca…
Primordial black hole formation and abundance: contribution from the non-linear relation between the density and curvature perturbation
Sam Young, Ilia Musco, Christian T. Byrnes
The formation and abundance of primordial black holes (PBHs) arising from the curvature perturbation is studied. The non-linear relation between and the density contrast…
Testing the SZ-based tomographic approach to the thermal history of the universe with pressure-density cross-correlations: Insights from the Magneticum simulation
Sam Young, Eiichiro Komatsu, Klaus Dolag
The thermal Sunyaev-Zeldovich effect contains information about the thermal history of the universe, observable in maps of the Compton parameter; however, it does not contain i…
The power spectrum on small scales: Robust constraints and comparing PBH methodologies
Andrew D. Gow, Christian T. Byrnes, Philippa S. Cole +1
We compare primordial black hole (PBH) constraints on the power spectrum and mass distributions using the traditional Press Schechter formalism, peaks theory, and a recently develo…
Primordial black holes in non-Gaussian regimes
Sam Young, Christian T. Byrnes
Primordial black holes (PBHs) can form in the early Universe from the collapse of rare, large density fluctuations. They have never been observed, but this fact is enough to constr…
Influence of large local and non-local bispectra on primordial black hole abundance
Sam Young, Donough Regan, Christian T. Byrnes
Primordial black holes represent a unique probe to constrain the early universe on small scales - providing the only constraints on the primordial power spectrum on the majority of…
Calculating the mass spectrum of primordial black holes
Sam Young, Christian T. Byrnes, Misao Sasaki
We reinspect the calculation for the mass fraction of primordial black holes (PBHs) which are formed from primordial perturbations, finding that performing the calculation using th…
Primordial Non-Gaussianity
P. Daniel Meerburg, Daniel Green, Muntazir Abidi +175
Our current understanding of the Universe is established through the pristine measurements of structure in the cosmic microwave background (CMB) and the distribution and shapes of…
Application of peaks theory to the abundance of primordial black holes
Sam Young, Marcello Musso
We consider the application of peaks theory to the calculation of the number density of peaks relevant for primordial black hole (PBH) formation. For PBHs, the final mass is relate…
Primordial black hole isocurvature modes from non-Gaussianity
Raphaël van Laak, Sam Young
Primordial black holes (PBHs) are black holes that might have formed in high density regions in the early universe. The presence of local-type non-Gaussianity can lead to large-sca…
Structure formation with primordial black holes: collisional dynamics, binaries, and gravitational waves
M. Sten Delos, Antti Rantala, Sam Young +1
Primordial black holes (PBHs) could compose the dark matter content of the Universe. We present the first simulations of cosmological structure formation with PBH dark matter that…
Primordial black holes with an accurate QCD equation of state
Christian T. Byrnes, Mark Hindmarsh, Sam Young +1
Making use of definitive new lattice computations of the Standard Model thermodynamics during the quantum chromodynamic (QCD) phase transition, we calculate the enhancement in the…
The impact of distant fly-bys on the rate of binary primordial black hole mergers
Sam Young, Adrian S. Hamers
By performing Monte Carlo simulations of the evolution of binary primordial black hole (PBH) systems, we estimate the effect of distant encounters with single PBHs upon the coalesc…
Primordial black hole formation during the QCD phase transition: threshold, mass distribution and abundance
Ilia Musco, Karsten Jedamzik, Sam Young
Primordial black hole (PBH) formation during cosmic phase transitions and annihilation periods, such as the QCD transition or the -annihilation, is thought to be particular…
BandNet: A Neural Network-based, Multi-Instrument Beatles-Style MIDI Music Composition Machine
Yichao Zhou, Wei Chu, Sam Young +1
In this paper, we propose a recurrent neural network (RNN)-based MIDI music composition machine that is able to learn musical knowledge from existing Beatles' songs and generate mu…
Computing the abundance of primordial black holes
Sam Young
An accurate calculation of their abundance is crucial for numerous aspects of cosmology related to primordial black holes (PBHs). For example, placing constraints on the primordial…
Constraining the early universe with primordial black holes
Sam Young
In this thesis, the effect of non-Gaussianity upon the abundance of primordial black holes (PBHs), and the implications of such an effect are considered. It is shown that even smal…