Abel Lawrence Peirson
I am a Ph.D student in Physics at Stanford University, where I research
theoretical astrophysics and applications of artifical intelligence as a
NASA FINESST fellow.
I am also interested in theoretical neuroscience, geophysical fluid dynamics, accelerator physics and plasma physics.
I received my bachelors and masters (MPhys) in Physics from the University of Oxford,
Christ Church, where I specialised in theoretical and particle physics.
I have spent time at CERN working on beam parameter measurement software for the
CLIC test facility's electron-positron collider and at the
University of Science and Technology of China working on plasma confinement in the
KMAX axisymmetric tandem mirror machine.
At Stanford I have recently worked on visual unsupervised learning in the
NeuroAILab and on developing a 2D path integration model in the fly
brain with the Druckmann Lab. I currently focus on astrophysics, characterising the
polarization behaviour of astrophysical jets and improving X-ray polarization sensitivty using machine learning for the
Outside of Physics, I designed an AI that generates memes: Dank Learning.
What started as a fun class project ended up being featured on
Inspired, I worked together with Dylan Freedman to create the free iOS app
Dank Learning so anyone can use the AI to generate memes.
I discuss the work in the
NVIDIA AI podcast and its implications
for the future of jewellery (yes this is real) at the Pratt Institute.
A current fun side project I am excited about is making exoplanet inspired art.
Besides my research, I enjoy engaging in scientfic outreach. I have recently become a
Wonderfest Science Envoy; I look forward to improving my public speaking
and communicating science to public audiences through the program. I am a
science pen pal, an
undergraduate student mentor
and a leading member of the Stanford Astronomical Society. I also enjoy competing for the
Stanford Judo Club and the Stanford Triathlon Club.
I'm currently interested in how the geometry of relativistic jets affects their polarized emission, the role of fluid mechanics in
jet evolution and how gravitational lensing might affect the observed polarization. Furthermore, I am trying to incorporate AI in
searches for rare blazar lensing events, improve IXPE's polarization sensitivity,
and take Dank Learning to the next stage.
Deep Ensemble Analysis for X-ray Polarimetry
Nuclear Instruments and Methods in Physics Research A , 2020
Using Deep ensembles to improve IXPE's sensitivity.
In order to measure polarization using a GPD, a distribution of photoelectron angles must be extracted
from noisy images of their individual tracks on a hexagonal grid. We use a convolutional neural network
architecture to predict the initial photoelectron angle and its uncertainty for each track image, as
well as the absorption point and energy. By combining predictions from an ensemble of networks in a
weighted maximum likelihood analysis we estimate the polarization fraction and EVPA of the X-ray source.
The Polarization Behavior of Relativistic Synchrotron Self-Compton Jets
The Astrophysical Journal, 2019
Exploring the expected synchrotron self-Compton polarization from blazar jets. A continuation of our multizone jet model.
For low-synchrotron peaked blazars, the X-ray emission will be dominated by synchrotron self-Compton. Understanding
what polarization levels IXPE is likely to see in this case is important
for distinguishing between hadronic and leptonic blazar emission models. We find that our multizone model recovers
simple predictions for SSC polarization, but describes new dependencies on jet viewing geometry. Importantly we find that a
rise in synchrotron polarization fraction at high energies is guaranteed by basic relativity considerations.
Prospects for Detecting X-Ray Polarization in Blazar Jets
The Astrophysical Journal, 2019
A study in the detectability of X-ray polarization in blazars for IXPE.
Using the models developed in the adjacent relativistic jet papers and optical polarization observations
by RoboPol, we are able to make predictions of the average expected X-ray polarization fraction.
This work will help the IXPE team choose appropriate first year observing targets.
The X-ray Polarization Probe Mission Concept
Decadal Survey on Astronomy and Astrophysics , 2020
A white paper for the upcoming Decadal survey introducing XPP, a second generation X-ray polarimeter that will cover
0.2 - 60keV!
Hopefully we will demonstrate the potential of imaging X-ray polarimeters with IXPE.
The Polarization Behavior of Relativistic Synchrotron Jets
The Astrophysical Journal, 2018
Using simple helical geometry and relativistic aberration effects to explain blazar polarization angle rotations.
Follow up paper for the synchrotron self-Compton emission coming soon.
Dank Learning: Generating Memes Using Deep Neural Networks
A.L.Peirson V, E.M.Tolunay
Accepted to Advances in Intelligent Systems and Computing, 2018
An image captioning system that can take any image and turn it into a first generation meme.
Uses pre trained Inception CNN followed by an LSTM with temperature selection for language generation. Trained on a dataset of over 300,000 image caption pairs.
Transverse Beam Phase-Space Measurement Experience at CTF3
S.Dobert, L.Malina, L.Martin,
A.Peirson Serratosa, T.Persson, J.Roberts, A.Rollings, Piotr Skowroński, Frank Tecker
8th International Particle Accelerator Conference, 2017   ,
Characterising the transverse phase space of the CTF3 beam before and after beam recombination with the Delay Loop.
I'm indebted to Dylan Freedman for introducing me to the very American
concept of a side project -- as such many of my projects are collaborations with him. For fun and more...
Making and displaying unique exoplanet inspired art.
We bought a 1982 HP7470a plotter printer and we
make it plot starfields around exoplanets. Check out our gallery of all the exoplanets we
know of! (We can plot other astronomical objects too... The image on the left is M51: the whirlpool galaxy).
this one was mainly D (I still smash him at the game though); one of my main contributions was including a poisson distribution for generating threadable gaps
in the curves. We have also made a 3d version in Unity: Achtung, 3die Kurve!, not available online yet.