# Seminars this semester

Series:

Sep 24 Thu Abhishek Rajhans (Inter-University Center for Astronomy and Astrophysics (IUCAA), Pune, India) European Solar Physics Online Seminars (ESPOS)
10:00 Zoom Forward modelling and energetics of Hi-C brightenings

Abstract:
The Solar coronal heating problem remains a persistent challenge in astrophysics. Parker postulated back in 1988 that the heating of corona should be dominated by small energy dissipation events, referred to as nanoflares. However, there have not yet been any confirmed observations of individual nanoflares. Hi-C reported unique bright points with energies ranging between log[E(ergs)] = 24-25. Those brightenings were also identified in AIA passbands. Here, I will describe 0-D hydrodynamical simulations to forward model these tiny brightenings, study their energetics, and discuss possible implications for coronal heating.

Sep 24 Thu Abhishek Rajhans (Inter-University Centre for Astronomy and Astrophysics, IUCAA (IN)) SP2RC/ESPOS
11:00 Zoom Forward modelling and energetics of Hi-C brightenings

Abstract:
The Solar coronal heating problem remains a persistent challenge in astrophysics. Parker postulated back in 1988 that the heating of corona should be dominated by small energy dissipation events, referred to as nanoflares. However, there have not yet been any confirmed observations of individual nanoflares. Hi-C reported unique bright points with energies ranging between log[E(ergs)] = 24-25. Those brightenings were also identified in AIA passbands. Here, I will describe 0-D hydrodynamical simulations to forward model these tiny brightenings, study their energetics, and discuss possible implications for coronal heating.

Sep 30 Wed Evgeny Shinder (Sheffield) Algebraic Geometry Learning Seminar
02:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 1/12: Basic invariants and examples

Sep 30 Wed Visakan Balakumar (Sheffield) Cosmology, Relativity and Gravitation
15:00 Blackboard Collaborate Quantum superradiance on static black hole space-times

Abstract:
We study the quantum analogue of the classical process of superradiance for a massless charged scalar field on a charged black hole space-time. We show that an “in” vacuum state, which is devoid of particles at past null infinity, contains an outgoing flux of particles at future null infinity. This radiation is emitted in the superradiant modes only, and is nonthermal in nature.

Oct 1 Thu Rekha Jain (Sheffield) Plasma Dynamics Group
16:00 Meet Frequency power spectra of Alfvén waves in a solar coronal arcade: Discrete or Continuous?

Abstract:
In this talk I will present theoretically computed frequency power spectra for shear Alfvén waves excited in a solar coronal arcade. I investigate two separate perturbations, a cosine-modulated Gaussian perturbation and an impulsive driver. The arcade is assumed to consist of potential magnetic field lines embedded in stratified plasma. In principle, the nature of the frequency power spectra can constrain the size and the type of driver.

Oct 2 Fri Teimuraz Zaqarashvili (University of Graz, Austria) SP2RC seminar
13:00 Meet Rossby waves and solar activity variations

Abstract:
Recent progress in observations of Rossby-type waves on the Sun revived the interests towards the waves. Though the hydrodynamic Rossby waves are well studied in the Earth context, the ubiquitous existence of magnetic fields in the atmosphere/interior of the Sun requires to study the waves in magnetohydrodynamics. The talk will cover the recent direct observations of Rossby waves on the Sun, theoretical development of magneto-Rossby wave theory and the possible connection of the waves to observed long and short term variations in solar magnetic activity.

Oct 7 Wed Reinder Meinsma Algebraic Geometry Learning Seminar
02:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 2/12: Curves on surfaces, rational and algebraic equivalence of divisors

Oct 7 Wed Katy Clough (Oxford) Cosmology, Relativity and Gravitation
15:00 Blackboard Collaborate Initial conditions for inflation

Abstract:
Inflation solves a number of problems in early universe cosmology but potentially introduces some new ones regarding how it was able to get started in the first place. In this talk I will explain these issues in the context of single field slow roll inflationary models, and discuss how they might restrict the phase space of initial conditions and early universe models that we consider valid. I will describe work I have done using numerical relativity to investigate the problem in the non-linear regime.

Oct 8 Thu Lucia Kleint (Leibniz Institute for Solar Physics (KIS), Germany)) European Solar Physics Online Seminars (ESPOS)
10:00 Zoom GREGOR - Optics Redesign, Updates, and First Images

Abstract:
GREGOR is Europe’s largest solar telescope. It has undergone significant upgrades and changes from 2018-2020 to improve the image quality, instrumentation, and operation. Particularly, a complete redesign of the optics laboratory was performed by KIS to obtain diffraction-limited images from the blue to the infrared. The new optics setup was completed while “trapped” on the mountain during the lockdown and we obtained first light images in July 2020. In this talk, I will summarize the most important updates, explain the new optics setup, and show the improved images.

Oct 8 Thu Lucia Kleint (Leibniz Institute for Solar Physics (KIS), Germany) SP2RC/ESPOS
10:00 Zoom GREGOR - Optics Redesign, Updates, and First Images

Abstract:
GREGOR is Europe’s largest solar telescope. It has undergone significant upgrades and changes from 2018-2020 to improve the image quality, instrumentation, and operation. Particularly, a complete redesign of the optics laboratory was performed by KIS to obtain diffraction-limited images from the blue to the infrared. The new optics setup was completed while “trapped” on the mountain during the lockdown and we obtained first light images in July 2020. In this talk, I will summarize the most important updates, explain the new optics setup, and show the improved images.

Oct 14 Wed Alberto Cobos Rabano (Sheffield) Algebraic Geometry Learning Seminar
02:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 3/12: Intersection theory on surfaces, adjunction formula

Oct 14 Wed Indira Chatterji (University of Nice) Pure Maths Colloquium
14:00 Meet Group ring conjectures and relative hyperbolicity

Abstract:
The idempotent conjecture is that there should be no idempotent in the group ring of a torsion-free group. I will discuss this conjecture, as well as associated conjectures in some geometric context, and will use them as an excuse to discuss hyperbolicity and introduce relative hyperbolicity, a context in which some of these conjectures are still open.

Oct 14 Wed Jose Cembranos (Complutense, Madrid) Cosmology, Relativity and Gravitation
15:00 Blackboard Collaborate Disformal dark matter from brane-worlds

Abstract:
Scalar particles coupled to the Standard Model fields through a disformal coupling arise in different theories, such as massive gravity or brane-world models. We will review the main phenomenology associated with such particles. Distinctive disformal signatures could be measured at colliders and with astrophysical observations. The phenomenological relevance of the disformal coupling demands the introduction of a set of symmetries, which may ensure the stability of these new degrees of freedom. In such a case, they constitute natural dark matter candidates since they are generally massive and weakly coupled. We will illustrate these ideas by paying particular attention to the branon case, since these questions arise naturally in brane-world models with low tension, where they were first discussed.

Oct 15 Thu Prof. Robertus Erdelyi (University of Sheffield) SP2RC seminar
10:00 Zoom (Meeting ID: 953 3817 1418) UK-SOSS: Waves and oscillations in the solar atmosphere

Abstract:
Satellite and ground-based observations from e.g. SOHO, TRACE, STEREO, Hinode, SDO and IRIS to DST/ROSA, IBIS, CoMP, STT/CRISP have all provided a wealth of evidence of waves and oscillations present in a wide range of spatial and temporal scales of the magnetised solar atmosphere. Our understanding about localised solar structures has been considerably changed in light of these superb spatial and temporal resolution observations. However, MHD waves not only enable us to perform sub-resolution solar magneto-seismology (SMS) but are also potential candidates to carry and damp the observed non-thermal energy in localised MHD waveguides. First, we will briefly outline the basic recent developments in MHD wave theory focussing on linear MHD waves both in symmetric and asymmetric waveguides. This latter may be an important aspect for the fantastic kitty: DKIST. Next, we will concentrate on the role of the most frequently studied wave classes, including the mysterious Alfven, and magneto-acoustic sub-classes of kink and sausage waves. Finally, we will address how solar MHD waves, swirls and solar jet formation may be related. We will argue to unite MHD wave and jet theories and make efforts to develop a common modelling platform with solar applications. An example will be shown where prevalent swirls, in the form of Alfven pulses, propagate upwards through the solar atmosphere dragging with them jets and reach the chromospheric layers. We will argue why this maybe seen as an important step towards understanding better the heating problem of the solar atmosphere.

Oct 15 Thu George Haller (ETH Zurich (Switzerland)) Plasma Dynamics Group
13:00 Meet Objective material barriers to the transport of momentum and vorticity

Abstract:
I discuss a recent theory for material surfaces that maximally inhibit the diffusive transport of a dynamically active (i.e., velocity-dependent) vector field, such as the linear momentum, the angular momentum or the vorticity, in three-dimensional unsteady flows. These diffusion barriers provide physics-based, observer-independent boundaries of dynamically active coherent structures. Instantaneous limits of these Lagrangian diffusion barriers mark objective Eulerian barriers to short-term active transport. I show how active diffusion barriers can be identified with active versions of Lagrangian coherent structure (LCS) diagnostics. In comparison to their passive counterparts, however, active LCS diagnostics require no significant fluid particle separation and hence provide substantially higher-resolved Lagrangian and Eulerian coherent structure boundaries from shorter velocity data sets. I illustrate these results on two-dimensional turbulence and three-dimensional wall-bounded turbulence.

Oct 20 Tue Haluk Sengun (Sheffield) Number Theory seminar
11:00 Google meet C*-algebras associated to locally compact groups and the Selberg trace formula

Abstract:
Given a locally compact group G, one can obtain C*-algebras by taking various completions of the convolution algebra of integrable functions on G. These C*-algebras sit in the intersection of representation theory, index theory and non-commutative geometry. In this talk, we will describe an identity, obtained in joint work with Bram Mesland (Leiden) and Hang Wang (Shanghai), that involves the K-groups of the C*-algebras of a semisimple Lie group G and of a cocompact lattice H in G. We will then argue that this identity is a K-theoretic analgoue of the celebrated Selberg trace formula. The talk is planned to be of expository nature.

Oct 20 Tue Alberto Cobos Rabano Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Alberaic Surfaces 4/12: Numerical equivalence, effective cone, numerical criterion for ampleness

Oct 21 Wed Atsushi Higuchi (York) Cosmology, Relativity and Gravitation
15:00 Blackboard Collaborate The Hartle-Hawking vacuum state in the Schwinger-Keldysh formalism for interacting scalar field theory

Abstract:
Schwarzschild and de Sitter spacetimes are spacetimes with bifurcate Killing horizons. It is known that the preferred vacuum state (the Hartle-Hawking state) in quantum field theory in these spacetimes is a thermal state in the static patch. For example, it is the thermal state with the Hawking temperature outside the horizon in the Schwarzschild case. It is also accepted that this state is obtained by analytic continuation from the corresponding Euclidean theory. In this talk, I will make this statement more precise in the context of the Schwinger-Keldysh (or in-in) perturbation theory. (This is a joint work in progress with William C C de Lima.)

Oct 22 Thu Ricardo Gafeira (University of Coimbra (PT)) SP2RC/ESPOS
10:00 Zoom link: https://zoom.us/j/165498165 (Meeting ID: 165 498 165) Modernization of the spectroheliograph of Coimbra

Abstract:

Oct 27 Tue Abhishek Saha (Queen Mary) Number Theory seminar
11:00 Google meet The Manin constant and p-adic bounds on denominators of the Fourier coefficients of newforms at cusps

Abstract:
The Manin constant $c$ of an elliptic curve $E$ over $\mathbb{Q}$ is the nonzero integer that scales the differential $\omega_f$ determined by the normalized newform $f$ associated to $E$ into the pullback of a Néron differential under a minimal modular parametrization$\phi\colon X_0(N)_{\mathbb{Q}} \twoheadrightarrow E$. Manin conjectured that $c = \pm 1$ for optimal parametrizations. I will talk about recent work that makes progress towards this conjecture by establishing an integrality property of $\omega_f$ necessary for this conjecture to hold. Our result implies in particular that $c \mid \mathrm{deg}(\phi)$ under a minor assumption at $2$ and $3$ that is not needed for cube-free $N$ or for parametrizations by $X_1(N)_{\mathbb{Q}}$. We reduce the above results to $p$-adic bounds on denominators of the Fourier expansions of $f$ at all the cusps of $X_0(N)_{\mathbb{C}}$. We succeed in proving stronger bounds in the more general setup of newforms of general weight and levels by approaching the problem representation-theoretically. These idea is to study the $p$-adic valuations of the values of the Whittaker newform of $\mathrm{GL}_2$ over a nonarchimedean local field of characteristic 0, using techniques that were originally developed by me in the context of the analytic sup-norm problem. For local fields of odd residue charactertistic, this allows us to ultimately reduce to the classical facts about $p$-adic valuations of Gauss sums. To overcome obstacles at 2, we analyze nondihedral supercuspidal representations of $\mathrm{GL}_2 (\mathbb{Q}_2)$. This is joint work with K\k{e}stutis \v{C}esnavi\v{c}ius and Michael Neururer.

Oct 27 Tue George Moulantzikos Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 5/12: Birational maps, blow ups, contractions of (-1)-curves

Oct 28 Wed Clara Loeh (University of Regensburg) Pure Maths Colloquium
14:00 Meet Amenable covers

Abstract:
A cover of a space by open subsets is amenable if these subsets all induce amenable images on the level of the fundamental group. In analogy with the LS-category, one can ask how small of an amenable cover one can find for a given space. By Gromov's vanishing theorem, simplicial volume is an example of an obstruction against the existence of small amenable covers. In this talk, I will put this result into context and I will briefly sketch an alternative proof for the vanishing theorem (joint work with Roman Sauer).

Oct 28 Wed Harry Desmond (Oxford) Cosmology, Relativity and Gravitation
15:00 Blackboard Collaborate Fifth force searches in galaxies

Abstract:
Fifth forces generically follow from new dynamical fields, and hence are ubiquitous in extensions to the standard model. Broad classes of Lagrangian exhibit "screening mechanisms" which hide the fifth force in high-density environments such as the Milky Way, while keeping it operative on larger scales. I will describe the search for fifth forces which act differently on different components of galaxies, e.g. through screening. First, I model the gravitational environments of the local Universe to determine the screening properties of real galaxies and the strength of the fifth-force field over space. I then use this information to forward-model two signals in galaxy morphology -- displacements of stars and gas and warping of stellar disks -- and hence infer fifth-force parameters with a Bayesian likelihood framework. Taking ~16,000 HI-cross-optical detections from the ALFALFA and SDSS surveys and ~4,000 galactic disk images from the Nasa Sloan Atlas, I set the strongest constraints to date on astrophysical fifth forces. Two particularly interesting applications are to f(R) and models such as coupled quintessence in which the fifth force acts only in the dark sector: for the former I require f_R0 < 1.4x10^-8 in the Hu-Sawicki model, and for the latter a fifth-force strength <10^-4 times that of gravity.

Oct 29 Thu Inigo Arregui (Instituto de Astrofisica de Canarias (Spain)) Plasma Dynamics Group
16:00 Meet Bayesian coronal seismology

Abstract:
Coronal seismology is based on the remote diagnostics of physical conditions in the solar corona by comparison between model predictions and observations of wave activity. Our lack of direct access to the physical system of interest makes information incomplete and uncertain so our conclusions are at best probabilities. Bayesian inference is increasingly being employed in the area, following a general trend in solar and astrophysical research. In this seminar, I first justify the use of a Bayesian probabilistic approach to seismology diagnostics and explain its philosophy and methodology. Then, I report on recent results that demonstrate its feasibility and advantage in applications to coronal loops, prominences and extended regions of the corona. To finish, I suggest other areas of current interest where the use of Bayesian methods could contribute to improve our understanding on the structure, dynamics and heating of the corona.

Nov 3 Tue Pol van Hoften (KCL) Number Theory seminar

Nov 3 Tue Yannik Schuler Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 6/12: Ruled surfaces

Nov 4 Wed Ulrich Pennig (University of Cardiff) Pure Maths Colloquium
14:00 Meet Bundles of Algebras - Dixmier-Douady Theory and Beyond

Abstract:
Intuitively a bundle of algebras is a collection of algebras continuously parametrised by a topological space. In operator algebras there are (at least) two different definitions that make this intuition precise: Continuous C(X)-algebras provide a flexible analytic point of view, while locally trivial C*-algebra bundles allow a classification via homotopy theory. The section algebra of a bundle in the topological sense is a C(X)-algebra, but the converse is not true. In this talk I will compare these two notions using the classical work of Dixmier and Douady on bundles with fibres isomorphic to the compacts as a guideline. I will then explain joint work with Marius Dadarlat, in which we showed that the theorems of Dixmier and Douady can be generalized to bundles with fibers isomorphic to stabilized strongly self-absorbing C*-algebras. An important feature of the theory is the appearance of higher analogues of the Dixmier-Douady class.

Nov 4 Wed Jean-Luc Lehners (Max-Planck-Institute, Potsdam) Applied Mathematics Colloquium
14:00

Nov 5 Thu (Institut d’Astrophysique Spatiale, IAS (FR)) SP2RC/ESPOS
00:00

Nov 10 Tue George Moulantzikos Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 7/12: Rational and del Pezzo surfaces

Nov 11 Wed Sira Gratz (University of Glasgow) Pure Maths Colloquium
14:00 Meet

Nov 11 Wed Lisa Glaser (Vienna) Cosmology, Relativity and Gravitation
15:00 remote TBA

Nov 12 Thu SP2RC seminar
10:00 LT 11 UK Solar Online Seminar Series (UK-SOSS) monthly seminar:

Nov 12 Thu Francisco Guzman (Universidad Michoacana de San Nicolas de Hidalgo, Mexico) Plasma Dynamics Group
16:00 Remote A code that solves the equations of MHD coupled to radiation

Abstract:
Our code is based on a finite volume discretization, uses high-resolution shock-capturing flux formulae of the HLL class. Concerning the MHD part, we use the divergence cleaning method to preserve the non-monopoles constraint. For radiation, at the moment, we use the M1 closure relation within the gray body approximation. The evolution equations for radiation become stiff for high opacities, for which we use an implicit-explicit evolution method, which allows the use of a standard integration time-step. We present our code's status and mention the solar physics scenarios where we expect to produce some applications.

Nov 17 Tue Ariel Weiss (Jerusalem) Number Theory seminar
11:00 J11

Nov 17 Tue Yirui Xiong (Sheffield) Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 8/12: Minimal models (nef K^2 or P^2 or ruled), uniqueness

Nov 18 Wed Andreagiovanni Reina (CS, Sheffield)
14:00 Meet Collective Decision Making: From Bees to Robots via Multiscale Modelling

Abstract:
I will give an overview of my studies on modelling and simulating collective decision making in distributed systems. Such systems, found in biology, sociology, and engineering, are composed of a large number of interacting individuals that coordinate in order to reach a consensus. The main phases of the collective decision making process consist of identifying the available options, estimating their quality, and selecting the best option or any of them. I will present the main results of my research in understanding and designing each of these phases. Collective systems are inherently difficult to analyse as the stochastic nonlinear interactions between individuals can give rise to complex emergent dynamics. Therefore, I employ a collection of advanced techniques, commonly defined as multiscale modelling. Relying on a set of methods, rather than a single one, gives the benefit of having complementary techniques addressing one another's limitations. In fact, through multiscale modelling, it is possible to analyse the systems at various levels of complexity and detail, from macroscopic group-level dynamics to microscopic individual-level behaviour, and from noise-free deterministic models to stochastic spatial descriptions. I finally shed a light on the recently developed opensource software for automated multiscale modelling. This software, called MuMoT, can also be a useful resource for remote teaching. For more info on MuMoT see (Marshall et al. PlosOne 2019) or MuMoT live notebook (https://mumot.readthedocs.io/). Bio: Dr Andreagiovanni Reina is a Research Fellow in Collective Robotics at the University of Sheffield, UK. He is currently working on the DiODe project (Distributed Algorithms for Optimal Decision-Making) led by Prof. James Marshall, and is the Principal Investigator of the Swarm Awareness project (https://swarmawareness.group.shef.ac.uk/). Andreagiovanni is the researcher responsible for more than 900 Kilobot robots and the related Augmented Reality for Kilobot (ARK) infrastructure at Sheffield Robotics. He holds a PhD in applied sciences from IRIDIA (Marco Dorigo's AI-Laboratory) of the Université Libre de Bruxelles, Belgium, and an M.Sc. in computer engineering from Politecnico di Milano, Italy. He has been a researcher in five European projects on distributed robotic systems since 2009. In December 2020, he plans to return to Brussels with an FNRS Fellowship on modelling heterogeneity in decentralised consensus. Full info at http://areina.staff.shef.ac.uk.

Nov 18 Wed Sara Arias de Reyna (University of Seville) Pure Maths Colloquium
14:00 Meet

Nov 18 Wed Andreagiovanni Reina (CS, Sheffield) Applied Mathematics Colloquium
14:00 Meet Collective Decision Making: From Bees to Robots via Multiscale Modelling

Abstract:
Abstract: I will give an overview of my studies on modelling and simulating collective decision making in distributed systems. Such systems, found in biology, sociology, and engineering, are composed of a large number of interacting individuals that coordinate in order to reach a consensus. The main phases of the collective decision making process consist of identifying the available options, estimating their quality, and selecting the best option or any of them. I will present the main results of my research in understanding and designing each of these phases. Collective systems are inherently difficult to analyse as the stochastic nonlinear interactions between individuals can give rise to complex emergent dynamics. Therefore, I employ a collection of advanced techniques, commonly defined as multiscale modelling. Relying on a set of methods, rather than a single one, gives the benefit of having complementary techniques addressing one another's limitations. In fact, through multiscale modelling, it is possible to analyse the systems at various levels of complexity and detail, from macroscopic group-level dynamics to microscopic individual-level behaviour, and from noise-free deterministic models to stochastic spatial descriptions. I finally shed a light on the recently developed opensource software for automated multiscale modelling. This software, called MuMoT, can also be a useful resource for remote teaching. For more info on MuMoT see (Marshall et al. PlosOne 2019) or MuMoT live notebook (https://mumot.readthedocs.io/). Bio: Dr Andreagiovanni Reina is a Research Fellow in Collective Robotics at the University of Sheffield, UK. He is currently working on the DiODe project (Distributed Algorithms for Optimal Decision-Making) led by Prof. James Marshall, and is the Principal Investigator of the Swarm Awareness project (https://swarmawareness.group.shef.ac.uk/). Andreagiovanni is the researcher responsible for more than 900 Kilobot robots and the related Augmented Reality for Kilobot (ARK) infrastructure at Sheffield Robotics. He holds a PhD in applied sciences from IRIDIA (Marco Dorigo's AI-Laboratory) of the Université Libre de Bruxelles, Belgium, and an M.Sc. in computer engineering from Politecnico di Milano, Italy. He has been a researcher in five European projects on distributed robotic systems since 2009. In December 2020, he plans to return to Brussels with an FNRS Fellowship on modelling heterogeneity in decentralised consensus. Full info at http://areina.staff.shef.ac.uk.

Nov 18 Wed Elisa Maggio (Sapienza, Rome) Cosmology, Relativity and Gravitation
15:00 Blackboard Collaborate TBA

Nov 19 Thu (Queen’s University Belfast, Astrophysics Research Centre (UK)) SP2RC/ESPOS
00:00

Nov 24 Tue Jaclyn Lang (Oxford) Number Theory seminar

Nov 24 Tue Cristina Manolache (Sheffield) Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 9/12: Surfaces with k = 0 (K3, Enriques, abelian, bielliptic)

Nov 25 Wed Ailsa Keating (University of Cambridge) Pure Maths Colloquium
14:00 Meet

Nov 25 Wed Ivonne Zavala (Swansea) Cosmology, Relativity and Gravitation
15:00 remote TBA

Dec 1 Tue Neil Dummigan (Sheffield) Number Theory seminar
11:00 Google meet Lifting congruences of modular forms to half-integral weight

Dec 1 Tue Reinder Meinsma Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 10/12: Elliptic surfaces

Dec 2 Wed Yemon Choi (University of Lancaster) Pure Maths Colloquium
14:00 Meet

Dec 2 Wed Andrew Krause (Oxford) Applied Mathematics Colloquium
14:00

Dec 2 Wed Andrew Gow (Sussex) Cosmology, Relativity and Gravitation
15:00 Blackboard Collaborate TBA

Dec 3 Thu (Leibniz Institute for Astrophysics Potsdam (DE)) SP2RC/ESPOS
00:00

Dec 8 Tue Jun Su (Cambridge) Number Theory seminar
11:00 J11 TBA

Dec 8 Tue Ananyo Dan Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 11/12: Surfaces of general type

Dec 9 Wed Kathryn Hess (École Polytechnique Fédérale de Lausanne) Pure Maths Colloquium
14:00 Meet

Dec 9 Wed Gary Mirams (Nottingham) Applied Mathematics Colloquium
14:00

Dec 10 Thu SP2RC seminar
10:00 LT 11 UK Solar Online Seminar Series (UK-SOSS) monthly seminar:

Dec 10 Thu Richard Morton (University of Northumbria) Plasma Dynamics Group
16:00 TBA

Abstract:
TBA

Dec 15 Tue Evgeny Shinder (Sheffield) Algebraic Geometry Learning Seminar
14:00 online in Blackboard collaborate (please e-mail Evgeny for the link) Algebraic Surfaces 12/12: Final overview of the classification of surfaces

Dec 16 Wed Marina Illiopoulou (University of Kent) Pure Maths Colloquium
14:00 Meet

Dec 16 Wed Konstantinos Zygalakis (Edunburgh) Applied Mathematics Colloquium
14:00

Dec 16 Wed Antonia Micol Frassino (ICC, Barcelona) Cosmology, Relativity and Gravitation
15:00 Blackboard Collaborate TBA

Dec 17 Thu (University of Sheffield, Solar Physics and Space Plasma Research Centre (UK)) SP2RC/ESPOS
00:00

Jan 21 Thu SP2RC seminar
13:00 LT 11 UK Solar Online Seminar Series (UK-SOSS) monthly seminar:

Jan 27 Wed Theo Torres Vicente (Nottingham) Cosmology, Relativity and Gravitation
15:00 remote TBA