Mon 24 Nov 13:00: Title to be confirmed
Abstract not available
- Speaker: Andreas Schachner (Munich U. and Cornell U.)
- Monday 24 November 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Gonzalo Villa.
Mon 27 Oct 13:00: Title to be confirmed
Abstract not available
- Speaker: Joseph Conlon (Oxford U.)
- Monday 27 October 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Gonzalo Villa.
Mon 06 Oct 13:00: Title to be confirmed
Abstract not available
- Speaker: Lucien Heurtier (King's College London)
- Monday 06 October 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Gonzalo Villa.
Mon 13 Oct 13:00: Title to be confirmed
Abstract not available
- Speaker: Ivonne Zavala (Swansea U.)
- Monday 13 October 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Gonzalo Villa.
Tue 08 Jul 11:15: Optimizing Data Delivery and Scalable HI Profile Classification for the SKA Era: Infrastructure and Science Challenges at the Spanish SRC
This talk presents ongoing work at the Spanish SKA Regional Centre (esSRC) in the context of the SRC Net 0.1. The first part focuses on the development of efficient data delivery techniques from the distributed Rucio-based storage system to the SRC infrastructure and, ultimately, to user workspaces. Several approaches have been evaluated to support science-ready access, yet current solutions often involve unnecessary data duplication in user areas, resulting in increased usage of storage and computational resources. To address this, we have prototyped mechanisms based on file linking, caching, and data reuse, enabling more efficient access paths for users. While these methods show promising improvements in terms of performance and resource usage, challenges remain, particularly in terms of orchestration, scalability, and compatibility with existing workload managers. The second part presents advances in the automated classification of neutral hydrogen (HI) profiles using machine learning methods, building on previous work [Parra et al., 2024, arXiv:2501.11657]. We outline a roadmap for extending these techniques to handle the data volumes expected from the SKA Observatory. This includes developing scalable pipelines capable of ingesting and processing large spectral datasets in a reproducible and efficient manner, and adapting the classification models to cope with the diversity and complexity of the SKA data products.
- Speaker: Dr. Manu Parra-Royón (Astrophysics Institute of Andalucia - Spanish National Research Council)
- Tuesday 08 July 2025, 11:15-12:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Tue 01 Jul 11:15: The Most Ambitious Radio Astronomy Endeavour of the 21st Century? Science, Technology and Engineering Dialogues in a Large-scale Project
The presentation will open with some reflections on the early part of the Square Kilometre Array (SKA) project, where questions asked about engineering realities constraining science aspirations were raised. Early encounters between Scientists and Engineers considered Radio Frequency Interference (RFI) as one of the constraints. Some formative developments of this specific Radio Astronomy (RA) project, with a focus on the XDM , KAT7 and then MeerKAT in South Africa, will be introduced and related to unexpected RFI . The picture will then be widened to unpack an understanding of RFI and ElectroMagnetic Compatibility (EMC) for RA and science projects more generally. Two European examples will be considered. A short diversion into the language that EMC engineers use in RFI and what RA presents as uv-plane data will be taken.
- Speaker: Prof. Howard Reader
- Tuesday 01 July 2025, 11:15-12:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Tue 01 Jul 11:15: Title TBC
The presentation will open with some reflections on the early part of the Square Kilometre Array (SKA) project, where questions asked about engineering realities constraining science aspirations were raised. Early encounters between Scientists and Engineers considered Radio Frequency Interference (RFI) as one of the constraints. Some formative developments of this specific Radio Astronomy (RA) project, with a focus on the XDM , KAT7 and then MeerKAT in South Africa, will be introduced and related to unexpected RFI . The picture will then be widened to unpack an understanding of RFI and ElectroMagnetic Compatibility (EMC) for RA and science projects more generally. Two European examples will be considered. A short diversion into the language that EMC engineers use in RFI and what RA presents as uv-plane data will be taken.
- Speaker: Prof. Howard Reader
- Tuesday 01 July 2025, 11:15-12:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Tue 01 Jul 11:15: Title TBC
The presentation will open with some reflections on the early part of the Square Kilometre Array (SKA) project, where questions asked about engineering realities constraining science aspirations were raised. Early encounters between Scientists and Engineers considered Radio Frequency Interference (RFI) as one of the constraints. Some formative developments of this specific Radio Astronomy (RA) project, with a focus on the XDM , KAT7 and then MeerKAT in South Africa, will be introduced and related to unexpected RFI . The picture will then be widened to unpack an understanding of RFI and ElectroMagnetic Compatibility (EMC) for RA and science projects more generally. Two European examples will be considered. A short diversion into the language that EMC engineers use in RFI and what RA presents as uv-plane data will be taken.
- Speaker: Prof. Howard Reader
- Tuesday 01 July 2025, 11:15-12:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Mon 23 Jun 13:00: The Hubble Tension and Primordial Magnetic Fields
The Hubble tension hints at a missing ingredient in the standard cosmological model describing the universe around the epoch of recombination. A stochastic magnetic field, if present in the plasma prior to last scattering, would induce baryon inhomogeneities and speed up the recombination process, reducing the sound horizon at last scattering and potentially helping to relieve the Hubble tension. I will review this proposal and provide an update on its current status.
- Speaker: Levon Pogosian (Simon Fraser University)
- Monday 23 June 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Louis Legrand.
Tue 08 Jul 11:15: Title TBC
Abstract TBC
- Speaker: Dr. Manu Parra-Royón (IAA-CSIC)
- Tuesday 08 July 2025, 11:15-12:00
- Venue: TBC.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Fri 13 Jun 13:00: Constraining Inflation with Numerical Relativity
Cosmic inflation is the leading paradigm for describing the early universe, addressing fundamental issues such as the horizon and flatness problems. However, a key unresolved question is the nature of its initial conditions. In this talk, I will discuss how numerical relativity helps studying inflationary spacetimes with inhomogeneous initial conditions, particularly in the presence of strong gravitational effects from large inhomogeneities. Numerical simulations allow us to map out the phase space of initial conditions that lead to sufficient duration of slow roll inflation versus those that do not. The results strongly depend on the inflationary model, with a rule of thumb that the models with near- or super-Planckian characteristic scales are more robust to matter and geometric inhomogeneities than those with sub-Planckian scales. We mainly focus on the study of α-attractor models and our simulation results allow us to find a lower bound on the tensor-to-scalar ratio r.
- Speaker: Panos Giannadakis, Queen Mary University of London
- Friday 13 June 2025, 13:00-14:00
- Venue: Potter room/Zoom.
- Series: DAMTP Friday GR Seminar; organiser: Xi Tong.
Mon 16 Jun 13:00: A short history of KiDS cosmic shear measurements - a.k.a. Euclid from the ground
In this seminar, I will give a historical overview of the cosmic shear measurements conducted with the Kilo-Degree Survey (KiDS) and their cosmological implications. I will focus on the progress in methodology and systematic error control that has been achieved over the past decade, with a particular focus on the observational problems that were solved to greatly increase the robustness of these analyses. I will present the final KiDS-Legacy results and highlight the lessons learned from KiDS that are most relevant for Euclid.
- Speaker: Hendrik Hildebrandt (Ruhr University Bochum)
- Monday 16 June 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Louis Legrand.
Thu 12 Jun 14:00: The enigmatic long-period radio transients
The long-period radio transients are a newly-discovered class of Galactic radio sources that produce pulsed emission lasting tens of seconds to several minutes, repeating on timescales of tens of minutes to hours. Such cadence is unprecedented, and there is currently no clear emission mechanism or progenitor that can explain the observations, which include complex polarisation behaviour, pulse microstructure, and activity windows that range from hours to decades.
Could they be ultra-long period magnetars, and connected to the phenomenon of Fast Radio Bursts? Could they be white dwarf pulsars, defying the expectations of the magnetic field evolution of these stellar remnants? In this talk I will describe the ten discoveries made so far, informative simulations of their evolution, the potential physical explanations, and the prospects for detecting more of these sources in ongoing and upcoming radio surveys, that will help uncover their true nature.
- Speaker: Prof. Natasha Hurley-Walker (Curtin University)
- Thursday 12 June 2025, 14:00-15:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Mon 16 Jun 14:00: Free floating planets and their possible origins
In recent years, free floating planets, i.e. those planets not found to be in a planetary system and with no observable companions, have begun to be found in microlensing and direct imaging surveys. Observations have shown that they have a wide variety of masses, ranging from terrestrial-like to giant planets. Microlensing surveys predict that there could be on order tens of free floating planets per star in the Milky Way. How these planets form and arrive on their observed trajectories remains a very open and intriguing question.
Whilst there are many mechanisms for forming free floating planets, e.g. ejections from planet-planet interactions or gravitational collapse of gas within molecular clouds, very few models have predicted the properties of free floating planets on a global scale. In this talk I will present the outcomes of state-of-the-art circumbinary planet formation models, that naturally produce a large abundance free floating planets per system. I will show the resulting mass and velocity distributions arising from the models, which will then be extended to include stellar populations of both single and binary stars, taking into binary fractions, and separations. The population distributions show clear observable features that can be investigated by future missions such as Roman, where evidence of these features will directly point to the specific formation pathways of specific planets, as well as informing on the processes of the planet forming environment in which they originated.
- Speaker: Gavin Coleman [Queen Mary University London]
- Monday 16 June 2025, 14:00-15:00
- Venue: MR14 DAMTP and online.
- Series: DAMTP Astrophysics Seminars; organiser: Thomas Jannaud.
Mon 20 Oct 13:00: Title to be confirmed
Abstract not available
- Speaker: Enea Di Dio (University of Geneva)
- Monday 20 October 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Louis Legrand.
Mon 17 Nov 13:00: Title to be confirmed
Abstract not available
- Speaker: Boryana Hadzhiyska (University of California, Berkeley)
- Monday 17 November 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Louis Legrand.
Thu 12 Jun 11:15: The enigmatic long-period radio transients
The long-period radio transients are a newly-discovered class of Galactic radio sources that produce pulsed emission lasting tens of seconds to several minutes, repeating on timescales of tens of minutes to hours. Such cadence is unprecedented, and there is currently no clear emission mechanism or progenitor that can explain the observations, which include complex polarisation behaviour, pulse microstructure, and activity windows that range from hours to decades.
Could they be ultra-long period magnetars, and connected to the phenomenon of Fast Radio Bursts? Could they be white dwarf pulsars, defying the expectations of the magnetic field evolution of these stellar remnants? In this talk I will describe the ten discoveries made so far, informative simulations of their evolution, the potential physical explanations, and the prospects for detecting more of these sources in ongoing and upcoming radio surveys, that will help uncover their true nature.
- Speaker: Prof. Natasha Hurley-Walker (Curtin University)
- Thursday 12 June 2025, 11:15-12:00
- Venue: Martin Ryle Seminar Room, Kavli Institute.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Tue 10 Jun 11:15: Intuitive knowledge systems for discovery
Join us for an exploration of how intuitive knowledge systems might complement current approaches in scientific discovery. Drawing from conversations during her fellowship at the Cavendish, artist Akeelah Bertram examines the acknowledged limits of current calculation systems and the role of intuition for receiving unknown phenomena. Through readings from her developing publication “Sacred Architecture,” she reflects on parallel knowledge systems, drawing from Caribbean congregational practices and embodied ways of knowing. This talk explores questions about the convergence of rigorous scientific inquiry with intuitive methodologies, considering what might emerge when different ways of knowing are held in dialogue.
- Speaker: Akeelah Bertram (Cavendish Arts Science Fellow)
- Tuesday 10 June 2025, 11:15-12:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Mon 09 Jun 13:00: Pulsar Timing Arrays and Astrometry: Going Beyond the Hellings-Downs correlation
The detection of gravitational waves (GWs) by pulsar timing arrays (PTAs) opens new avenues for probing the physics of GW sources at nanohertz frequencies. In the same frequency band, astrometric observations may also enable future GW detections. It is therefore important to investigate the potential for cross-correlating these two complementary approaches. Accordingly, I will discuss three topics related to the characterization of the stochastic gravitational-wave background using pulsar timing arrays and astrometry. The potential detection of its kinematic dipole. The prospects for measuring its circular polarization. A new method for identifying the possible presence of scalar polarization in the GW background.
- 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.
Mon 02 Jun 13:00: Cracks in the Standard Cosmological Model: Anomalies, Tensions, and Hints of New Physics
The ΛCDM model has long served as the standard paradigm in cosmology, offering a remarkably successful description of the Universe’s evolution. Yet, as observational precision continues to improve, persistent tensions have emerged across a range of probes, including the well-known Hubble constant discrepancy. While individual datasets may each align with ΛCDM, their collective interpretation reveals significant discordances that challenge the model’s internal consistency. In this talk, I will review the most prominent tensions in modern cosmology and assess their implications. I will present recent results pointing to hints of dynamical dark energy and interactions within the dark sector. I will also reflect on the growing influence of methodological choices, such as dataset selection and model assumptions, in shaping our cosmological conclusions.
- Speaker: Eleonora Di Valentino (University of Sheffield)
- Monday 02 June 2025, 13:00-14:00
- Venue: SPECIAL LOCATION - CMS, MR4, Pav A basement.
- Series: Cosmology Lunch; organiser: Thomas Colas.