About Rin

About — Rin Ray

ABOUT ME

My name is Catherine Ray (they/them), and I’m a mathematician and artist. My current math research is on arithmetic patterns in homotopy theory and physics.

Rin Ray
CV MATH CV OTHER
Pastel

Before I was in math, I worked mostly in scientific simulation, autonomous robotics, and medical technology. I continue to work in chronic pain research, which you can read about here.

Here for the math? Skip to the research ↓

THE PATH

I am currently a postdoc at Uni-Münster in the Arithmetic and Homotopy Theory Working Group led by Thomas Nikolaus and Christopher Deninger.

Interview — How an Inventor becomes a Mathematician

A blackboard of zeta function computations

Before that, I graduated from George Mason University at 16 with a B.S. in Computational Physics, and accepted the Thiel Fellowship in 2014 to develop medical technology and study mathematics under my mentor, Edward Frenkel. I graduated with my Master’s degree from UChicago working with Peter May and Kazuya Kato (加藤 和也), and with my PhD from Northwestern working with Paul Goerss and Yifeng Liu.

THE OTHER STUDIO

I primarily work with pastels, acrylic, spray paint and polaroids. When I spray I make colorful street murals of creatures. Please enjoy this small collection of my art.

Away from the desk I rock climb, write short stories, speak intermediate German, beginners Russian and Spanish, embarrassingly “robotic” American Sign Language, read braille, and play trombone and ukulele.

pastels acrylic spray paint polaroids tattoo design

SEE THE GALLERY →

BEFORE MATH

tl;dr my technical background is mainly in robotics (machine learning and SLAM), and computational physics. In autumn 2014 I began teaching myself algebraic topology full time, and did not stop.

Robotics and autonomous systems

A hexapod that followed people around, and a Rubik’s cube solving robot2011

my first two robotics projects

Positronics Division, George Washington University Robotics LabSummer 2012

Our team smoothed joint movement of the Willow Garage Personal Robot 2 (PR2) and improved load equalization. I programmed the PR2 to autonomously “learn” to place objects in holes of the corresponding shape, using only past motor position commands and the finger gripper sensors.

SLAM and motion planning on the ARDroneFall 2013

Polyglass — a Google Glass app that computes a human pulse from the video feedHackMIT 2013

joint with Kartik Talwar and Spencer Hewett

Simulation and computational physics

Resistive switching behaviour of flexible TiO2Spring 2012

a memristor project at the Chemistry and Physics Department of Mary Baldwin College, which is where I became interested in physical examples of nonlinear systems

Modes of conductive polyhedra2012

a side project, out of fascination with argon plasma glow produced by introducing an RF source at 2.45 GHz to a conductive cavity

Machine learning and language

Automating the collection and classification of lab-animal vocalizationslate 2013 – mid 2014

how I dipped my toes into audio processing

Medical and assistive technology

Improving mobility devicesSummer 2013 – Spring 2014

a nonprovisional patent was submitted in Dec 2014 for the five pressure sore relief mechanisms that grew out of this

NeuroprostheticsSummer 2014

starting on the software side with convergence analysis of common decoder algorithms, then moving to the hardware side and optical recording methods

Complex systems

Visiting Researcher, Santa Fe InstituteJan 2015

gave a seminar on Simplifying Multiscale Modeling. I still think about applications of topology to multiscale modeling, and occasionally venture to consider modeling complex systems of a biological nature with an eye toward immunotherapy and neuroscience.

CONTACT ME

Curiosity is welcome
fractalcows@gmail.com
My work email
cray@uni-muenster.de

You will find the name Catherine Ray on my old research papers and Rin Ray on my newer works — these both refer to the same person. I prefer Rin nowadays.

PUBLISHED

Towards Directed Collapsibility

joint with R. Belton, R. Brooks, S. Ebli, L. Fajstrup, B. T. Fasy, N. Sanderson, E. Vidaurre · Advances in Mathematical Sciences, vol. 21, pp. 255–271, 2020

arXiv

PREPRINTS

IN PROGRESS

Zeta Functions in Homotopy Theory

Syntomic cohomology of ring spectra and a T(h)-local zeta function

joint with Gabe Angelini-Knoll

Toward Categorifying the relationship of Symplectic L-functions and Reidemeister Torsion

Riemann–Roch for Reidemeister torsion in K-theory and L-theory

L-genera and Localizations in K-theory

joint with Daniel Berwick-Evans, Natalia Pacheco-Tallaj

All Bernoulli Numbers in Homotopy Theory Are Shiftson hiatus

joint with Andres Mejia and Noah Riggenbach · connecting Kervaire–Milnor to Quillen–Lichtenbaum using the compatibility of K(𝕊) and LK(1)K(ℤ)

Moduli Stacks of Curves in Homotopy Theory

The group cohomology of the maximal finite subgroups of the Lubin–Tate action is the E2 page needed to capture all p-torsion information in the stable homotopy groups of spheres. My thesis (2023) attempts to resolve the 40-year-old open problem of describing the Lubin–Tate action for all maximal finite subgroups.

It does so by outlining a universal way to build a geometric model using a moduli stack of G-curves given a subgroup G. A key insight is to replace the role of level structures with higher ramification information. To make the thesis more digestible, I have broken it up into three parts, the last of which is forthcoming. The only nontrivial p-torsion for odd primes is found at heights pk−1(p−1).

Writhing Jewels: A Conjectural Description of the Lubin–Tate Action via Moduli Stacks of G-Curves for h = pk−1(p−1)

The Eigenvalues of Frobenius of Artin–Schreier–Witt Curves are Gauss Sums

new families of Newton strata in the Torelli locus

Note toward this — PDF

EXPOSITORY

K-theoretic Tate–Poitou Duality Seminarcoming soon

March 2025

My two Master’s theses

Lubin-Tate illustration