Gravitation & Cosmology Physicist (PhD) at Mercor

Gravitation, Cosmology and Astrophysics Physicist (PhD) | $80-110/hr | Remote | 10 hrs/week

About the work

CritPt is a public benchmark of research-level physics challenges testing whether frontier AI models can do genuine physics research reasoning. The team is engaging physicists to work on research-level problems in their own subfield: creating problems, solving them, reviewing completed work, or auditing it. The specific assignment is agreed once you are matched to an area. This is research-grade work: everything you produce must be complete enough for another specialist in your subfield to follow and verify independently, so written reasoning is part of every assignment.

Research areas

Four areas are open, three in torsionful gravity and axion inflation, one in high-energy astrophysics:

• Einstein-Cartan and Nieh-Yan axion inflation: perturbations and power spectrum - Einstein-Cartan-Palatini first-order gravity, Nieh-Yan topological invariant, tetrad formalism torsion, axion inflation, Mukhanov-Sasaki mode equation, primordial curvature power spectrum.
• Einstein-Cartan and Nieh-Yan axion inflation: FRW background dynamics - Palatini formulation, tetrad and spin-connection variables, axionic natural inflation, numerical integration of background field equations.
• Dynamical Chern-Simons gravity in Palatini formalism, parity-violating inflation - torsion and contorsion decomposition, Chern-Simons coupling to the Pontryagin density, parity violation, slow-roll inflation, numerical integration of coupled field equations.
• High-energy astrophysics: blazar jets, photohadronic emission, multimessenger constraints - relativistic beaming and Doppler boosting, photopion production, electromagnetic cascades, one-zone blazar modeling, variability-based causality constraints.

Requirements

• PhD in gravitation, cosmology, astroparticle physics or a closely related field. Postdocs, research scientists and junior faculty are the strongest fit; senior PhD students with a strong first-author record are welcome.
• Published work on the specific phenomenon above, not the adjacent one. Working in modified gravity is not enough if your papers are not on torsion, Nieh-Yan or Chern-Simons terms.
• Verifiable publication record: three to five representative papers with arXiv IDs or DOIs, ideally from the last five years. First author strongly preferred. Papers are checked against the public record.
• Sign-convention discipline: precision with tetrad and spin-connection conventions.
• Working proficiency with LaTeX, Python, SymPy and Jupyter. Gaps are acceptable if declared honestly.
• English at B2 or above, including written reasoning.

Application steps

Apply and complete the attached form, listing up to five areas you fit best, each with an arXiv ID or DOI of your own paper as proof. Papers and authorship are then verified. 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 only where needed; most applicants will not see one.

Commitment and pay

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