Thomas Helfer, Ph.D.

Artificial Intelligence | High Performance Computing | Black Holes

About Me

Research Fellow at the Institute for Advanced Computational Science at Stony Brook  

Bridging AI, High-Performance Computation, and Astrophysics for Unraveling Black Hole Mysteries

My Story

Hello! I’m Thomas Helfer, and my academic and professional path has been driven by fascination with exploring new topics in science. My journey began at Imperial College London, where I delved into the intense world of theoretical physics during my master’s program. Transitioning from theoretical to computational physics for my Ph.D. was exciting. Having started with very little experience in coding, I was quickly able to upstart and get into the deep end of highly parallelized code in C++, even able to contribute to state-of-art codebases like GRChombo (now GRTL). My Ph.D. was a blend of theoretical concepts and practical simulations, offering me a comprehensive insight into the world of computational physics.

My first postdoc position marked another significant turn in my career. I became increasingly captivated by deep learning, particularly superresolution. The remarkable achievements of DLSS in video games demonstrated to me the potential of these methods in scientific research, particularly in black hole simulations. This realization steered me towards deep learning, leading to my current role at the Institute for Advanced Computational Science at Stony Brook University. At Stony Brook, my focus is on leveraging deep learning to enhance simulations, exploring its applications not just in speeding up computational processes but also in broadening the scope of deep learning in scientific research. What I love about my research is the opportunity to merge my background in physics with the exciting possibilities of AI, continually learning and applying these innovative techniques to new scientific questions.

Fig: A set of AI-generated galaxies using state-of-art diffusion models. Every single block is a synthetic galaxy, almost indistinguishable from real ones.

Fig: A rendering of a black hole disk using my ray-tracing code (github). The black hole distorts the surrounding light; this distortion is so strong that some light makes multiple turns around the black hole, creating multiple copies of the disk (in red and blue). A similar depiction of a black hole is seen in the movie “Interstellar” by Christopher Nolan. 

My achievements

Over the years, I’ve made significant contributions to our understanding of numerical relativity, with a particular emphasis on advancing gravitational wave detection technologies. My research has culminated in the publication of over 20 papers in various prestigious scientific journals with now almost a 1000 citations, underscoring my ability to conduct cutting-edge research in this dynamic field. I’ve also had the privilege of sharing my insights with the global scientific community through more than 50 presentations at universities worldwide, showcasing my aptitude for effectively communicating complex technical information. As a mentor, I managed and supervised three Ph.D. students and led international, multi-institution research collaborations.

Selected projects

Upcoming PDExAI

Upcoming work applying ML methods to improve PDE methods for general relativity.

In collaboration with Thomas Edwards, James Alvey
SynthRAD AI competition

In this work we translated MRI images to CT images using Pix2Pix (cGAN) as well as a diffusion based model with Controlnet.

 

In collaboration with Jessica Dafflon [NIH], Walter Hugo Lopez Pinaya [King's College London]
Non-linearities in highly boosted black hole head-on merger

Published by PRL

ArXiv: 2208.07374 

In this work, we used simulations of highly boosted black holes to study the aftermath and if non-linear effects are needed to describe the process. 

 

In collaboration with Mark Ho-Yeuk Cheung, Vishal Baibhav, Emanuele Berti, Vitor Cardoso, Gregorio Carullo, Roberto Cotesta, Walter Del Pozzo, Francisco Duque, Estuti Shukla, Kaze W. K. Wong
Boson Star Ringdown

Published in CQG 

ArXiv: 2207.05690

with generated data available here 

Using new ideas and developments, we study and perform some of the longes simulations of a boson-star Ringdown ever performed. We find that the resulting gravitational waves are potential smoking gun signals for the existence of boson stars, an exotic cousin of neutron stars. 

In collaboration with Robin Croft, Bo-Xuan Ge, Miren Radia, Tamara Evstafyeva, Eugene A. Lim, Ulrich Sperhake, Katy Clough
Full overview over publications: See

Google Scholar

Open source code projects

PyInterpX

A highly performant, GPU compatible package for higher order interpolation in PyTorch

TorchGRTL

A translation of crucial parts of numerical relativity in torch for superresolition

Multimodal learning

A pytorch codebase for multimodal learning in Astrophysics

GRChombo (renamed GRTL)

An AMR based open-source code for numerical relativity simulations.

Boson Star solver

A python solver that produces fully general relativistic solution for many different types of scalar and proca stars.

Geodesic shooter

A C++ codebase to solve to explore spacetimes with geodesics.

Recent Events

Published new Github repo improved interpolation

A highly performant, GPU compatible package for higher order interpolation in PyTorch: link

Published new Github repo for accelerated learning in Torch

A repo in PyTroch that uses ports of the GRTL codebase rewritten in PyTorch for accelerated learning: link

IAIFI Boston-Area Astro ML Hackathon - Jan 2024

Started a project multimodal machine learning to connect Supernovae light-curves with images from their host-galaxies.

 

Visited JHU at department of applied math and Statistics - Oct 2023

The talk with the title “Using Deep Learning to enhance PDE solver for Black Hole Simulations” Slides available here. 

 

IAIFI Workshop artificial intelligence and physics workshop

A workshop presented by the IAIFI collaboration. More info here.

Cambridge Ellis School on Probabilistic Machine Learning

A Cambridge university Summer school. More info here.

Reports of work on non-linear modes in Popular Science

Click here to access the article. This also came along with a press-release by hopkins.

Education and work experience

Research Fellow in Applied Deep Learning
2023 -

Advancing AI applications in science 

Postdoc in Computational Physics
2019 - 2023

with Prof. Emanuele Berti – Groundbreaking work on non-linear physics of black holes (see press-release)

PhD in Computational Physics
2015 - 2020

Under the supervision of Prof. Eugene Lim – Won thesis prize under the best 20 thesis for this year at King’s College 

MSc in Theoretical Physics (QFFF)
2014 - 2015
– Graduated with Distinction
BSc in physics at ETH Zürich
2010 - 2014

Prices and Grants won

King’s Outstanding Thesis Prize 2021
TACC Computational Grant

Access to the Frontera cluster via the Pathways Allocations 

Excellence Scholarships of South Tirol

Leistungs stipendium der Provinz Bozen

Professional development

Deep Learning

IAIFI Summer School (AI in physics)

A MIT, Harvard, Northeastern, and Tufts summer school covering:
- Generative Artificial Intelligence
- Symmetries in Neural Networks
- Trasformers
- Statistical physics of Neural Networks
See more Details .

Ellis Summer School (Generative and probabilistic AI)

A Cambridge University summer school covering a plethora of topics ranging from reinforcement learning in robotics to theory of stochastic differential equations.
See more Details .

DeepLearn International School on Deep Learning

A school on Deep Learning covering various topics of AI applications in science.
See more Details

Certifications

Roughly 20 certifications spanning from deep learning to MLOps, AWS Cloud (SageMaster), Generative Adversarial Networks (GANs) as well as Natural Language Processing (NLP).
See more Details

High Performance Computing

C++ Intermediate

A four day course organised by the high performance centre (HPC) in Stuttgart

C++ Advanced

A four day course organised by the HPC in Stuttgart

Single-node Performance Optimisation

Two day course in Oxford, UK. Topics include: topics: Parallel IO, Derived Datatypes, Basic MPI-IO Calls, HDF5 and NetCDF

Intro to OpenMP and MPI

One day course in Portsmouth, UK

Advanced OpenMP

One day course at Imperial College London, UK

Argonne Training on
Extreme-Scale Computing

Two week prestigious school on HPC from the Argonne National Laboratory