Astrophysics

Quasinormal-mode frequencies characterize black-hole spacetimes and can be measured with gravitational waves, but small perturbations to the gravitational potential can substantially change the spectrum. This seminar studies that spectral instability in a time-domain waveform model. A frequency shift appears only after a delay set by the echo time between the perturbation and the primary potential. In the perturbative limit, the post-echo shift agrees with the usual frequency-domain result; outside that limit, the intermediate-time signal cannot be represented by a constant frequency shift.

Zack Gelles examines how black-hole rotation twists magnetic fields near light cylinders, where plasma accelerates into inflows and outflows. Semi-analytic models and simulations connect this structure to polarization changes detectable with radio interferometry, offering constraints on black-hole spin and relativistic jets. Kritti Sharma presents fast radio bursts as probes of cosmic baryons. Dispersion measures and secure host redshifts constrain gas in galaxy groups and clusters, while correlations with large-scale structure and other tracers map matter along burst sight-lines. The talk considers how future burst surveys can measure baryonic feedback and its evolution alongside other cosmological observations. Online via Stanford KIPAC Zoom. Friday 25 September 2026, 10:40–11:30 PDT (America/Los_Angeles; UTC−7). Follow Join the zoom meeting on the event page. The organizer lists faculty, staff, members and students as the audience. This is one session with two speakers; individual talk start times are not supplied.

Paco Villaescusa surveys the growing role of numerical simulations and AI in cosmology. Quijote and Backlight explore how much information about the Universe can be recovered beyond conventional summary statistics, including nonlinear structure and higher-order relationships. CAMELS addresses uncertainty in galaxy formation and other astrophysical processes, while DREAMS examines dark-matter predictions in the presence of baryonic effects. The seminar then considers automated research workflows through Denario, a system that develops hypotheses, plans analyses, writes and executes code, and interprets results. It discusses possibilities opened by combining simulation libraries with coordinated AI systems, while framing these as research directions. The speaker is a computational cosmologist at the Flatiron Institute.

Lurdes Ondaro Mallea examines whether current models of the kinematic Sunyaev–Zeldovich signal accurately recover diffuse baryons and the strength of astrophysical feedback. The analysis uses hydrodynamic simulations to generate mock stacked measurements for realistic DESI-like galaxy samples, separating contributions from gas density, velocities and nonlinear astrophysics. It tests baryonic changes to density and velocity fields, satellite galaxies, nonlinear velocities and velocity reconstruction. Neglecting satellites can underestimate halo gas fractions at today's measurement precision; further corrections become significant for future datasets. The talk explains how including these effects can improve gas-distribution measurements and assessments of feedback. Online via Zoom. Monday 28 September 2026, 11:00–12:00 PDT (America/Los_Angeles; UTC−7). Follow Join the zoom meeting on the organizer's event page. Lurdes Ondaro Mallea is affiliated with Cambridge. Organized by the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), Stanford University. This listing advertises the verified remote option.

The University of Cambridge's Handley Lab seeks a researcher to connect fundamental theories with cosmological and astrophysical observations using AI-assisted scientific software and GPU-accelerated inference. The role includes developing physical predictions, Bayesian methods including nested sampling, publishing research and shaping an independent research programme. The post is based at the Kavli Institute for Cosmology and Institute of Astronomy, with funding initially available until 30 September 2030. Appointment is at Grade 7 or Grade 9 according to experience; Grade 9 requires Faculty Board approval. Salary: £37,694–£59,966. Applications close on 25 September 2026 at 23:59 GMT, as stated by the employer. Submit a cover letter, CV, publications, research statement, evidence of computational skills and two academic referee contacts through the university recruitment system. A PhD, completed or near completion, in physics, astronomy, applied mathematics or a related field is required. Reference LG51052.

RAS Study or Research Projects grants normally provide £250–£5,000 for work advancing astronomy or geophysics, particularly activities and applicants underserved by other funding sources. Evidence of an application for matching support is required. The current pilot accepts applications continuously and assesses small grants at four annual cut-offs; the next is 30 September 2026. Applications after a cut-off move to the next round. This current overview supersedes the older two-deadline wording still present on individual scheme pages.

RAS grants normally contribute £250–£1,000 toward conference or meeting travel, registration and subsistence. Matching-funding applications must be evidenced; student support normally covers at most half the costs. Applicants must provide a submitted or planned talk/poster abstract. Meetings must occur between six weeks and six months after the assessment deadline. The current pilot accepts applications continuously and assesses small grants at four annual cut-offs; the next is 30 September 2026. Applications after a cut-off move to the next round. This current overview supersedes the older two-deadline wording still present on individual scheme pages.

Join Eduardo Bañados’s group to investigate early quasars and their environments. The postdoc will analyze JWST PRISM-DAWN integral-field spectroscopy, contribute to Euclid’s quasar programme, and help prepare and reduce Large Binocular Telescope observations. The full-time position lasts three years, with a negotiable start; the first half of 2027 is preferred. This vacancy belongs to the September 2026 Max Planck Postdoc Program call, which accepts applications until 13 October 2026 at 12:00 CEST through the official application platform.

Participation grants for the 2027 IAU General Assembly can support registration, accommodation, travel and childcare. Selection considers the applicant’s scientific contribution, the relevant committee’s abstract assessment, need, career stage and access to other funding. Applications are open and close on 15 January 2027 at 23:59 CET. Submit all abstracts and register before applying through the official platform in English. Grant applicants may defer payment while awaiting the decision, using the organizer’s stated registration procedure. Decisions are scheduled for 30 April 2027.

RAS Study or Research Projects grants normally provide £250–£5,000 for work advancing astronomy or geophysics, particularly activities and applicants underserved by other funding sources. Evidence of an application for matching support is required. The current pilot accepts applications continuously and assesses small grants at four annual cut-offs; the next is 30 September 2026. Applications after a cut-off move to the next round. This current overview supersedes the older two-deadline wording still present on individual scheme pages.

RAS grants normally contribute £250–£1,000 toward conference or meeting travel, registration and subsistence. Matching-funding applications must be evidenced; student support normally covers at most half the costs. Applicants must provide a submitted or planned talk/poster abstract. Meetings must occur between six weeks and six months after the assessment deadline. The current pilot accepts applications continuously and assesses small grants at four annual cut-offs; the next is 30 September 2026. Applications after a cut-off move to the next round. This current overview supersedes the older two-deadline wording still present on individual scheme pages.

Three-year fellowships at the Max Planck Institute for Astrophysics in Garching near Munich, Germany, supporting an independent research programme and interaction with institute researchers. Areas span stellar and binary astrophysics, transients, gravitational waves, computational astrophysics and cosmology, galaxies and supermassive black holes, star formation, large-scale structure, gravitational lensing, the cosmic microwave background and physical cosmology. Fellows receive computing resources, travel support and access to the wider Garching astronomy community. Published annual gross salary is EUR 67,500–77,700 depending on experience, with 30 days of holiday and public-service benefits. Applicants must have completed their PhD within the past six years. Submit a CV, publication list identifying accepted refereed papers, research statement covering previous work and plans at MPA (suggested three to five pages), and three referees through the official portal. A cover letter is optional. Applications and confidential reference letters are due 15 November 2026. The portal is currently accepting registrations for this call.