Tue 25 Mar 14:15: Brill-Noether loci of pencils with prescribed ramification
The geometry of curves carrying pencils with prescribed ramification is regulated by the so called adjusted Brill-Noether number. In this talk I will discuss the problem of existence and dimension of Brill-Noether varieties in this context and compare it to the classical one without imposed ramification. The new results are based on joint work with Andreas Leopold Knutsen.
- Speaker: Sara Torelli, Università degli studi di Torino.
- Tuesday 25 March 2025, 14:15-15:15
- Venue: CMS MR13.
- Series: Algebraic Geometry Seminar; organiser: Dhruv Ranganathan.
Tue 22 Apr 14:00: Distribution Learning Meets Graph Structure Sampling
This work establishes a novel link between the problem of PAC -learning high-dimensional graphical models and the task of (efficient) counting and sampling of graph structures, using an online learning framework. We observe that if we apply the exponentially weighted average (EWA) or randomized weighted majority (RWM) forecasters on a sequence of samples from a distribution P using the log loss function, the average regret incurred by the forecaster’s predictions can be used to bound the expected KL divergence between P and the predictions. Known regret bounds for EWA and RWM then yield new sample complexity bounds for learning Bayes nets. Moreover, these algorithms can be made computationally efficient for several interesting classes of Bayes nets. Specifically, we give a new sample-optimal and polynomial time learning algorithm with respect to trees of unknown structure and the first polynomial sample and time algorithm for learning with respect to Bayes nets over a given chordal skeleton.
Joint work with Sutanu Gayen (IIT Kanpur), Philips George John (NUS), Sayantan Sen (NUS), and N.V. Vinodchandran (U Nebraska Lincoln)
- Speaker: Arnab Bhattacharya (University of Warwick)
- Tuesday 22 April 2025, 14:00-15:00
- Venue: Computer Laboratory, William Gates Building, FW26.
- Series: Algorithms and Complexity Seminar; organiser: Tom Gur.
Tue 25 Mar 14:00: BSU Seminar: "A Nonparanormal Approach to Marginal Inference" This will be a free online seminar. To register to attend, please click on the link: https://cam-ac-uk.zoom.us/webinar/register/WN_xwbSLwLITemQeb8b-jk-Fg
Treatment effects for a novel therapy are typically measured by comparing marginal outcome distributions across study arms. While proper randomisation in randomised trials allows their estimation from observed outcome distributions, covariate adjustment is recommended to increase precision. However, for noncollapsible measures like odds or hazard ratios in logistic or proportional hazards models, conditioning on covariates changes the effect interpretation, and different covariate sets yield incomparable estimates.
In this talk, I introduce a novel nonparanormal model formulation for adjusted marginal inference allowing the estimation of the joint distribution of outcome and covariates. This approach offers not only the marginal treatment effect of interest for a wide range of outcome types but also an overall coefficient of determination and covariate-specific measures of prognostic strength. I will show how this method enhances precision of the marginal, noncollapsible effect – both theoretically and through empirical results.
This will be a free online seminar. To register to attend, please click on the link: https://cam-ac-uk.zoom.us/webinar/register/WN_xwbSLwLITemQeb8b-jk-Fg
- Speaker: Susanne Dandl, University of Zurich
- Tuesday 25 March 2025, 14:00-15:00
- Venue: Online Seminar.
- Series: MRC Biostatistics Unit Seminars; organiser: Alison Quenault.
Wed 26 Mar 11:00: Learning to See the World in 3D Teams link available upon request (it is sent out on our mailing list, eng-mlg-rcc [at] lists.cam.ac.uk). Sign up to our mailing list for easier reminders via lists.cam.ac.uk.
Humans can effortlessly construct rich mental representations of the 3D world from sparse input, such as a single image. This is a core aspect of intelligence that helps us understand and interact with our surroundings and with each other. My research aims to build similar computational models–-artificial intelligence methods that can perceive properties of the 3D structured world from images and videos. Despite remarkable progress in 2D computer vision, 3D perception remains an open problem due to some unique challenges, such as limited 3D training data and uncertainties in reconstruction. My goal will be to discuss these challenges and explain how my research addresses them by posing vision as an inverse problem, and by designing machine learning models with physics-inspired inductive biases.
Teams link available upon request (it is sent out on our mailing list, eng-mlg-rcc [at] lists.cam.ac.uk). Sign up to our mailing list for easier reminders via lists.cam.ac.uk.
- Speaker: Ayush Tewari (University of Cambridge)
- Wednesday 26 March 2025, 11:00-12:30
- Venue: Cambridge University Engineering Department, CBL Seminar room BE4-38..
- Series: Machine Learning Reading Group @ CUED; organiser: .
Thu 27 Mar 16:00: "Targeting CD4+ T Cells to Enhance Tumour Immunity"
This Cambridge Immunology and Medicine Seminar will take place on Thursday 27 March 2025, starting at 4:00pm, in the Ground Floor Lecture Theatre, Jeffrey Cheah Biomedical Centre (JCBC)
Speaker: Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute, Cardiff University
Title: “Targeting CD4 + T Cells to Enhance Tumour Immunity”
Host: Maike De La Roche & Tim Halim, CRUK Cambridge Institute
Refreshments will be available following the seminar.
- Speaker: Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute, Cardiff University
- Thursday 27 March 2025, 16:00-17:00
- Venue: Lecture Theatre, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus.
- Series: Cambridge Immunology Network Seminar Series; organiser: Ruth Paton.
Wed 26 Mar 16:00: Fractional Charge and Fractional Statistics & how they are connected
After a review of the history of the subject, I will discuss the claim that fractional charge by itself implies fractional statistics, and show that there is a loophole in the original argument for why this is the case. I will then provide an improved argument that also assumes that the system is in a fractional quantum Hall state. First I give a heuristic version of the argument and then a formal one. I also point out the failure of the original argument is connected to a 1-form t´Hooft anomaly in a Chern-Simons theory.
- Speaker: Prof. Thors Hans Hansson (Stockholm)
- Wednesday 26 March 2025, 16:00-17:30
- Venue: TCM Seminar Room.
- Series: Theory of Condensed Matter; organiser: Bo Peng.
Thu 19 Jun 17:00: Title to be confirmed
Abstract not available
- Speaker: Jujian Zhang (Imperial College London) and Arnaud Mayeux (The Hebrew University of Jerusalem)
- Thursday 19 June 2025, 17:00-18:00
- Venue: MR14 Centre for Mathematical Sciences.
- Series: Formalisation of mathematics with interactive theorem provers ; organiser: Anand Rao Tadipatri.
Fri 28 Mar 14:15: The Chow Ring of the Moduli Stack of Hyperelliptic Prym Pairs
The study of intersection theory on moduli spaces and stacks has a rich history, beginning with Mumford’s seminal 1983 paper, where he introduced the Chow ring with rational coefficients for the moduli space of smooth pointed curves of a given genus and its Deligne–Mumford compactification. This framework was later extended by Vistoli to Deligne–Mumford stacks, by Edidin and Graham to quotient stacks, and more generally by Kresch to both integral and rational coefficients. Since then, extensive research has been devoted to computing the intersection theory of various moduli stacks.
In this talk, we will focus on the integral version of Chow rings, which is generally less well understood. I will first review some known results in this direction. I will then outline the computation of the integral Chow ring of the moduli stack of hyperelliptic Prym curves, which are étale double covers of hyperelliptic curves—a result that Alessio Cela and I recently obtained. In the case of genus two, our results recover a previous computation by Cela and Lopez.
- Speaker: Alberto landi, Brown University
- Friday 28 March 2025, 14:15-15:15
- Venue: CMS MR13.
- Series: Algebraic Geometry Seminar; organiser: Dhruv Ranganathan.
Tue 25 Mar 14:15: Irreducibility of Severi varieties on toric surfaces
Severi varieties parametrize integral curves of fixed geometric genus in a given linear system on a surface. In this talk, I will discuss the classical question of whether Severi varieties are irreducible and its relation to the irreducibility of other moduli spaces of curves. I will indicate how tropical methods can be used to answer such irreducibility questions. The new results are from ongoing joint work with Xiang He and Ilya Tyomkin.
- Speaker: Karl Christ, Università degli studi di Torino
- Tuesday 25 March 2025, 14:15-15:15
- Venue: CMS MR13.
- Series: Algebraic Geometry Seminar; organiser: Dhruv Ranganathan.
Tue 25 Mar 10:00: Brill-Noether loci of pencils with prescribed ramification
The geometry of curves carrying pencils with prescribed ramification is regulated by the so called adjusted Brill-Noether number. In this talk I will discuss the problem of existence and dimension of Brill-Noether varieties in this context and compare it to the classical one without imposed ramification. The new results are based on joint work with Andreas Leopold Knutsen.
- Speaker: Sara Torelli, Università degli studi di Torino.
- Tuesday 25 March 2025, 10:00-11:00
- Venue: CMS MR13.
- Series: Algebraic Geometry Seminar; organiser: Dhruv Ranganathan.
Tue 20 May 13:10: Woe is Me!: Spatial Logic and Memory in the OIMOI Inscriptions of Selinous
In the ancient Greek city-state of Selinous in Sicily, there is a unique set of funerary inscriptions which directly lament the fate of the deceased. This formula lacks precedent elsewhere in the Greek world, and I explore how the content of these inscriptions interact with the space on which they are laid out, the memorial stones themselves, and the surrounding landscape. I argue that the negative space employed in many of the inscriptions speaks just as forcefully as the text itself, and that it renders memory in terms of absence, not presence.
- Speaker: Campbell Rosener
- Tuesday 20 May 2025, 13:10-14:00
- Venue: Richard King room, Darwin College.
- Series: Darwin College Humanities and Social Sciences Seminars; organiser: Matthew Jones.
Thu 27 Mar 16:00: Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute, Cardiff University
This Cambridge Immunology and Medicine Seminar will take place on Thursday 27 March 2025, starting at 4:00pm, in the Ground Floor Lecture Theatre, Jeffrey Cheah Biomedical Centre (JCBC)
Speaker: Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute, Cardiff University
Title: TBC
Host: Maike De La Roche & Tim Halim, CRUK Cambridge Institute
Refreshments will be available following the seminar.
- Speaker: Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute, Cardiff University
- Thursday 27 March 2025, 16:00-17:00
- Venue: Lecture Theatre, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus.
- Series: Cambridge Immunology Network Seminar Series; organiser: Ruth Paton.
Thu 27 Mar 14:00: Field-induced Multi-Q⃗ States in a Pyrochlore Heisenberg Magnet
In this talk, I will present a recent work on the J1-J3b classical Heisenberg model on the pyrochlore lattice in the presence of a magnetic field. We construct exact ground states of the model, which are non-coplanar multi-Q⃗ spin configurations with a large magnetic unit cell. Using linear spin wave theory, we show that entropy favours these multi-Q⃗ states at low temperatures in high magnetic fields. This is confirmed by Monte Carlo simulations, which we also use to map out a phase diagram. Lastly, we calculate the zero-temperature dynamical structure factor. Besides the usual Goldstone modes associated with the ordering Q⃗s, we find high-intensity gapless modes at momenta where there are no Bragg peaks.
- Speaker: Cecilie Glittum (Helmholtz-Zentum Berlin)
- Thursday 27 March 2025, 14:00-15:30
- Venue: TCM Seminar Room.
- Series: Theory of Condensed Matter; organiser: Bo Peng.
Fri 21 Mar 17:00: Surgical data using LLMs
Abstract not available
- Speaker: Hugo Georgenthum
- Friday 21 March 2025, 17:00-17:45
- Venue: Lecture Theatre 2, Computer Laboratory, William Gates Building.
- Series: Foundation AI; organiser: Pietro Lio.
Fri 09 May 12:00: Asymmetry in Supposedly Equivalent Facts: Pre-training Bias in Large Language Models
Understanding and mitigating hallucinations in Large Language Models (LLMs) is crucial for ensuring reliable content generation. While previous research has primarily focused on “when” LLMs hallucinate, our work explains “why” and directly links model behaviour to the pre-training data that forms their prior knowledge. Specifically, we demonstrate that an asymmetry exists in the recognition of logically equivalent facts, which can be attributed to frequency discrepancies of entities appearing as subjects versus objects. Given that most pre-training datasets are inaccessible, we leverage the fully open-source OLMo series by indexing its Dolma dataset to estimate entity frequencies. Using relational facts (represented as triples) from Wikidata5M, we construct probing datasets to isolate this effect. Our experiments reveal that facts with a high-frequency subject and a low-frequency object are better recognised than their inverse, despite their logical equivalence. The pattern reverses in low-to-high frequency settings, and no statistically significant asymmetry emerges when both entities are high-frequency. These findings underscore the influential role of pre-training data in shaping model predictions and provide insights for inferring the characteristics of pre-training data in closed or partially closed LLMs.
- Speaker: Zifeng Ding (University of Cambridge)
- Friday 09 May 2025, 12:00-13:00
- Venue: Room FW26 with Hybrid Format. Here is the Zoom link for those that wish to join online: https://cam-ac-uk.zoom.us/j/4751389294?pwd=Z2ZOSDk0eG1wZldVWG1GVVhrTzFIZz09.
- Series: NLIP Seminar Series; organiser: Suchir Salhan.
Thu 08 May 16:00: “Imaging the Immune System in Tissue Repair”
This Cambridge Immunology and Medicine Seminar will take place on Thursday 8 May 2025, starting at 4:00pm, in the Ground Floor Lecture Theatre, Jeffrey Cheah Biomedical Centre (JCBC)
Speaker: Professor Paul Kubes, Cumming School of Medicine, University of Calgary
Title: “Imaging the Immune System in Tissue Repair”
Abstract: Using a very simple model of tissue injury where a thermal probe is touched to the surface of a tissue and kills about 1000 cells has unveiled a very complex series of immune events that lead to complete repair in tissues like the liver. Neutrophils enter the site, clear the debris and leave again via the vasculature while monocytes and iNKT cells surround the injury and slowly the monocytes convert to a repair phenotype before entering and working with stellate cells to help to return the structure back to homeostasis. The outer compartment where the mesothelium has to regrow requires that peritoneal macrophages attach to the injury site take on a repair phenotype with the help of peritoneal mast cells and aid in repair. Some of these same principles apply to chronic injury and cancer.
Host: Tim Halim, CRUK Cambridge
Refreshments will be available following the seminar.
- Speaker: Professor Paul Kubes, Cumming School of Medicine, University of Calgary
- Thursday 08 May 2025, 16:00-17:00
- Venue: Lecture Theatre, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus.
- Series: Cambridge Immunology Network Seminar Series; organiser: Ruth Paton.
Fri 21 Mar 17:00: Surgical data using LLMs
Abstract not available
- Speaker: Speaker to be confirmed
- Friday 21 March 2025, 17:00-17:45
- Venue: Lecture Theatre 2, Computer Laboratory, William Gates Building.
- Series: Foundation AI; organiser: Pietro Lio.
Thu 01 May 16:00: Self or non-self? Detection of nucleic acids in the endolysosome
This Cambridge Immunology and Medicine Seminar will take place on Thursday 1 May 2025, starting at 4:00pm, in the Ground Floor Lecture Theatre, Jeffrey Cheah Biomedical Centre (JCBC)
Speaker: Professor Veit Hornung, Gene Center and Department of Biochemistry, University of Munich
Title: ‘Self or non-self? Detection of nucleic acids in the endolysosome’
Abstract: A central function of our innate immune system is to detect microbial pathogens by the presence of their nucleic acid genomes or their transcriptional or replicative activity. In mammals, a receptor-based system – represented by pattern recognition receptors (PRRs) – is primarily responsible for the detection of “non-self” nucleic acids. In recent years, tremendous progress has been made in identifying the key sensing and signaling components required for this complex task. The first group of PRRs identified as nucleic acid sensing receptors are the toll-like receptors (TLRs). TLRs are expressed as transmembrane receptors with their ligand binding domain facing either the extracellular space or the luminal compartment. A distinct evolutionary subset of TLRs is located in the endolysosomal compartment, which in the human system includes TLR7 , TLR8 and TLR9 . While TLR9 recognizes single-stranded DNA with unmethylated CG motifs, which are indeed suppressed in the host genome, TLR7 and TLR8 have evolved to recognize RNA degradation products. Although there has been considerable research on RNA -sensing TLRs, our understanding of their capability to differentiate between non-self and self-RNA remains limited, particularly considering the prevalence of self-RNA in the endolysosomal compartment. In this talk, I will provide an update on our recent work on this topic and present some novel insights into how TLR7 and TLR8 discriminate self from non-self.
Host: Felix Randow, MRC -LMB, Cambridge
Refreshments will be available following the seminar.
- Speaker: Prof. Dr. Veit Hornung, Gene Center Munich
- Thursday 01 May 2025, 16:00-17:00
- Venue: Max Perutz Lecture Theatre, MRC LMB, Francis Crick Avenue, Cambridge CB2 0QH .
- Series: Cambridge Immunology Network Seminar Series; organiser: Ruth Paton.
Thu 10 Apr 13:00: Raphael Mattiuz, Post-doctoral Fellow in Immunobiology, Mount Sinai
This Cambridge Immunology and Medicine Seminar will take place on Thursday 4 April 2025, starting at 4:00pm, in the Ground Floor Lecture Theatre, Jeffrey Cheah Biomedical Centre (JCBC)
Speaker: Raphael Mattiuz, Post-doctoral Fellow in Immunobiology, Mount Sinai
Title: TBC
Host:
Refreshments will be available following the seminar.
- Speaker: Raphael Mattiuz, Post-doctoral Fellow in Immunobiology, Mount Sinai
- Thursday 10 April 2025, 13:00-14:00
- Venue: Lecture Theatre, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus.
- Series: Cambridge Immunology Network Seminar Series; organiser: Ruth Paton.
Fri 23 May 14:00: Joint ChemBio and Synthesis RIG Seminar - Chemical Biology Tools for Measuring Drug Delivery
Abstract not available
- Speaker: Joshua Kritzer (Tufts University)
- Friday 23 May 2025, 14:00-15:00
- Venue: Dept. of Chemistry, Wolfson Lecture Theatre.
- Series: Synthetic Chemistry Research Interest Group; organiser: Jasmine Mitchell.