Fri 20 Jun 13:00: TBC
Abstract not available
- Speaker: Aron Kovacs, Queen Mary University of London
- Friday 20 June 2025, 13:00-14:00
- Venue: Potter room/Zoom.
- Series: DAMTP Friday GR Seminar; organiser: Xi Tong.
Fri 30 May 13:00: TBC
Abstract not available
- Speaker: Violetta Sagun, University of Southampton
- Friday 30 May 2025, 13:00-14:00
- Venue: Potter room/Zoom.
- Series: DAMTP Friday GR Seminar; organiser: Xi Tong.
Fri 16 May 13:00: TBC
Abstract not available
- Speaker: Benjamin Elder, Imperial College London
- Friday 16 May 2025, 13:00-14:00
- Venue: Potter room/Zoom.
- Series: DAMTP Friday GR Seminar; organiser: Xi Tong.
Fri 09 May 13:00: TBC
Abstract not available
- Speaker: Robbie Hennigar, Durham University
- Friday 09 May 2025, 13:00-14:00
- Venue: Potter room/Zoom.
- Series: DAMTP Friday GR Seminar; organiser: Xi Tong.
Mon 16 Jun 14:00: Title to be confirmed
Abstract not available
- Speaker: Gavin Coleman [Queen Mary University London]
- Monday 16 June 2025, 14:00-15:00
- Venue: Venue to be confirmed.
- Series: DAMTP Astrophysics Seminars; organiser: Thomas Jannaud.
Thu 05 Jun 14:00: Title to be confirmed
Abstract not available
- Speaker: Jonathan Squire [Otago, New Zealand]
- Thursday 05 June 2025, 14:00-15:00
- Venue: MR20 DAMTP and online.
- Series: DAMTP Astrophysics Seminars; organiser: Loren E. Held.
Mon 02 Jun 14:00: Title to be confirmed
Abstract not available
- Speaker: Florence Marcotte [Université Côte d'Azur, Nice, France]
- Monday 02 June 2025, 14:00-15:00
- Venue: MR14 DAMTP and online.
- Series: DAMTP Astrophysics Seminars; organiser: Mattias Brynjell-Rahkola.
Mon 12 May 14:00: Title to be confirmed
Abstract not available
- Speaker: Maarit Korpi-Lagg [Helsinki/Espoo]
- Monday 12 May 2025, 14:00-15:00
- Venue: MR14 DAMTP and online.
- Series: DAMTP Astrophysics Seminars; organiser: Mattias Brynjell-Rahkola.
Mon 19 May 14:00: Title to be confirmed
Abstract not available
- Speaker: Morgan Williams [Imperial College London]
- Monday 19 May 2025, 14:00-15:00
- Venue: MR14 DAMTP and online.
- Series: DAMTP Astrophysics Seminars; organiser: Thomas Jannaud.
Tue 27 May 14:00: Title to be confirmed
Abstract not available
- Speaker: David Melon-Fuksman [MPIA Heidelberg]
- Tuesday 27 May 2025, 14:00-15:00
- Venue: MR4 DAMTP and online.
- Series: DAMTP Astrophysics Seminars; organiser: Loren E. Held.
Thu 29 May 14:00: Title to be confirmed
Abstract not available
- Speaker: Martin Pessah [NBIA Copenhagen]
- Thursday 29 May 2025, 14:00-15:00
- Venue: MR14 DAMTP and online.
- Series: DAMTP Astrophysics Seminars; organiser: Loren E. Held.
Tue 29 Apr 13:00: Formation of planetary cores in spontaneously generated dust traps during the secular evolution of magnetized protoplanetary disks
An outstanding gap in the current planet formation theory is about the first steps of the planet formation process; namely how, when and where the initially ISM like solid dust particles grow into pebbles and planetesimals, the building blocks of planetary cores. Protoplanetary disks provide the initial conditions for the planet formation process. They are weakly magnetized accretion disks that are subject to the magnetorotational instability (MRI), one of the main magnetized processes responsible for their angular momentum transport and gas turbulence. The nonideal magnetohydrodynamic (MHD) effects prevent the MRI from operating everywhere in PPDs, leading to a complex dichotomy between MRI active regions with higher gas turbulence and non-MRI regions with lower gas turbulence. In this talk, I will present the first numerical framework that describes the evolution of PPDs over millions of years powered by the MRI . It captures the MRI driven gas evolution via nonideal MHD calculations, which accounts for the dynamics and growth of the solid dust particles. An MRI powered mechanism that can spontaneously generate short- and long-lived pressure maxima in the PPD is unveiled. Within the long-lived pressure maxima, solid dust particles can be efficiently trapped, grow into pebbles, and reach high enough dust-to-gas mass ratios to potentially trigger the formation of planetesimals via the streaming instability. These planetesimals and pebbles can further rapidly interact to form planetary cores.
- Speaker: Timmy Delage (Imperial)
- Tuesday 29 April 2025, 13:00-14:00
- Venue: Ryle seminar room + ONLINE - Details to be sent by email.
- Series: Exoplanet Seminars; organiser: Dr Dolev Bashi.
Fri 25 Apr 11:30: The Thesan-Zoom simulations: Studying high-redshift galaxy formation with cosmological radiation-hydrodynamics simulations
Abstract not available
- Speaker: Ewald Puchwein (AIP)
- Friday 25 April 2025, 11:30-12:30
- Venue: Ryle Seminar Room, KICC + online.
- Series: Galaxies Discussion Group; organiser: Sandro Tacchella.
Mon 09 Jun 13:00: Title to be confirmed
Abstract not available
- Speaker: Gianmassimo Tasinato (Swansea University)
- Monday 09 June 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Thomas Colas.
Fri 25 Apr 13:00: Black hole radiation from non-vacuum initial states
Hawking derived the black hole thermal radiation state by comparing the vacuum state at the future null infinity I+ with that at the past null infinity I-. We revisit Hawking’s computation, considering a non-vacuum initial state at the past of the black hole geometry. We show in which cases the black hole radiation arising from the initial matter state differs from the well-known thermal state. We moreover classify what initial states are distinguishable from one another through measurements on the black hole radiation in this framework. Finally we provide a physical interpretation of the classification, using Algebraic Quantum Field Theory localisation.
- Speaker: Ali Akil, Hong Kong University
- Friday 25 April 2025, 13:00-14:00
- Venue: Potter room/Zoom: https://cam-ac-uk.zoom.us/j/88420112623?pwd=uogMItLtNT8pn4aks1hO4nJVmonbpV.1.
- Series: DAMTP Friday GR Seminar; organiser: Xi Tong.
Mon 06 Oct 13:00: Title to be confirmed
Abstract not available
- Speaker: Etienne Camphuis (Institut d'Astrophysique de Paris)
- Monday 06 October 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Thomas Colas.
Fri 23 May 11:30: Between the extremes -- the physics of the first stars, galaxies, and black holes
The emergence of the first sources 13.6 billion years ago had a profound effect on the Universe, initiating its last major phase-change and ending the so-called Cosmic Dark Ages. Unlocking the physics of those primordial sources thus represents a fundamental step towards a comprehensive understanding of the initial conditions that formed the building blocks for the Universe we see today. While Hubble painted a fairly straight forward picture, early JWST data revealed an infant Universe far more remarkable and exotic than previously thought, with hyper-luminous galaxies detected out to z=14, chemically-enriched and Nitrogen-enhanced interstellar media out to z=12, and apparently over-massive black holes to z=10. Are these sources representative of the global population, or do they reflect peculiar objects at a particular evolutionary phase? In this talk I will present efforts to address these questions through the spectroscopic study of statistical samples of high-redshift (z>5-14) galaxies with JWST /NIRSpec, establishing a benchmark for their chemical enrichment journeys, ISM conditions, (re)ionizing capabilities, and spectroscopic fingerprints. Additionally, I will showcase the importance of utilizing unbiased samples of galaxies to gain representative insight into the ISM conditions and evolutionary pathways of the most luminous populations uncovered by JWST .
- Speaker: Guido Roberts-Borsani (UCL)
- Friday 23 May 2025, 11:30-12:30
- Venue: Ryle Seminar Room, KICC + online.
- Series: Galaxies Discussion Group; organiser: Sandro Tacchella.
Fri 30 May 11:30: Chasing the Light: Shadowing, Collimation, and the Rapid Growth of Infant Black Holes
Observations with the James Webb Space Telescope (JWST) have uncovered a substantial population of high-redshift broad-line active galactic nuclei (AGNs) characterized by moderate luminosities, weak X-ray emissions, and faint high-ionization lines, challenging conventional models of AGN activity. In this talk I will propose that these sources are accreting at super-Eddington rates, and discuss how such accretion flows, shaped by thick disk geometries and anisotropic radiation fields, may provide new insights into black hole growth in the early Universe.
- Speaker: Piero Madau (UCSC)
- Friday 30 May 2025, 11:30-12:30
- Venue: Ryle Seminar Room, KICC + online.
- Series: Galaxies Discussion Group; organiser: Sandro Tacchella.
Fri 02 May 11:30: Exploring high-redshift quenched galaxies: from low-mass to massive
Abstract not available
- Speaker: William Baker (Dark)
- Friday 02 May 2025, 11:30-12:30
- Venue: Ryle Seminar Room, KICC + online.
- Series: Galaxies Discussion Group; organiser: Sandro Tacchella.
Fri 16 May 11:30: Towards understanding the epoch of reionization out to the cosmic dawn
Work on understanding the epoch of reionization has been galvanized in recent years by a series of observational and theoretical breakthroughs. These include the recognition that spatial structure in the Lyman-α forest retains signatures of reionization history, the discovery of galaxies and quasars deep in the reionization era by JWST , and renewed efforts to detect the redshifted 21-cm signal from cosmic dawn and the epoch of reionization. In this talk, I will present a series of results from our group that address the goal of understanding the evolving ionization state of the Universe, from cosmic dawn to the final stages of reionization. This includes new simulations of reionization, updated measurements of the mean free path of ionizing photons, improved constraints on the neutral hydrogen fraction from quasar damping wings, and interpretations of AGNs and LAEs discovered by JWST . I will describe our ongoing attempts to directly detect the neutral parts of the IGM for the first time using the 21-cm forest, and discuss the implications of JWST data for quasar growth during this era. Deeper into the reionization epoch, I will present new approaches to charting reionization using LAEs. Closer to cosmic dawn, I will highlight new radiative transfer models of Lyman-α coupling and a model-agnostic framework for combining JWST and 21-cm observations, including results from REACH . I will conclude by reviewing where we are and outlining key challenges ahead.
- Speaker: Girish Kulkarni (TIFR)
- Friday 16 May 2025, 11:30-12:30
- Venue: Ryle Seminar Room, KICC + online.
- Series: Galaxies Discussion Group; organiser: Sandro Tacchella.
