Stochastic Biophysics Physicist (PhD) at Mercor

Stochastic Biophysics Physicist (PhD) | $80-110/hr | Remote

Work on research-level physics problems for CritPt, a public benchmark testing whether frontier AI models can carry out genuine physics research reasoning rather than textbook problem solving. We are hiring physicists to create, solve, review or audit problems in their own subfield. The benchmark paper (arXiv:2509.26574) is recommended reading before applying. The work is contracted through Mercor.

The Work

You will work on research-level physics problems in your specific subfield: stochastic autocatalytic growth, the chemical master equation and branching processes. Depending on your publication record, assignments can include creating problems, solving them, reviewing completed work or auditing it. This is research-grade work, not volume work: everything you produce must be complete enough for another specialist to follow and verify independently, so written reasoning is part of every assignment.

Research Area

• Stochastic autocatalytic growth, chemical master equation, branching processes: autocatalytic reaction cycles, the stochastic Hinshelwood cycle, circulant matrix spectra, transient oscillations toward balanced exponential growth, moment hierarchies for reaction networks, and generating-function methods.
• If you also work on long-range dispersal, heavy-tailed jump processes or front propagation in range expansions, mention this on the application form. A closely related area sits in the statistical physics panel and draws on the same methods.

Requirements

• A PhD in biophysics, statistical physics, applied mathematics or a closely related field. Postdoctoral researchers, research scientists and junior faculty are the strongest fit; senior PhD students with a strong first-author record are welcome.
• Published work on stochastic growth or reaction-network dynamics specifically. You must have published on this phenomenon, not just in biophysics broadly. Command of the methods alone is not enough.
• A verifiable publication record: three to five representative papers with arXiv IDs or DOIs, ideally from the last five years, first author strongly preferred. Every paper listed will be checked against the public record.
• Your own papers demonstrating at least one of: chemical master equation and the stochastic Hinshelwood cycle; multi-type branching processes and circulant matrix spectra; moment hierarchies for reaction networks; or generating-function methods.
• Working proficiency with LaTeX, Python, SymPy and Jupyter. Familiarity with an agentic coding extension in VS Code is useful. Gaps are acceptable if declared honestly.
• English at B2 or above, including written reasoning.

Pay and Schedule

$80 to $110 per hour, set by depth of subdomain match. 10 hours per week, sustained across an 8 to 10 week window, starting immediately. Remote and asynchronous with no fixed hours.

Application Process

• Apply and complete the attached form, including an arXiv ID or DOI of your own paper as proof, your author position and the methods it demonstrates. A selection without proof is not scored.
• Papers and authorship are verified against the public record.
• You are either onboarded directly or invited to a short live alignment call to agree the area and assignment.
• A brief 30 to 45 minute assessment may be added where needed, but most applicants will not see one.