Found at least 20 result(s)
journal club Schaub Vladimir (KCL)
at: 01:00 - 01:00 KCL, Strand room: Norfolk Building 342N abstract: | Keywords: |
regular seminar Daphne Ezer (University of York)
at: 01:00 - 01:00 KCL, Strand room: S5.20 abstract: | Plants undergo several key developmental transitions, such as the decision to flower, that farmers would like to synchronise to maximise their yields. In this talk I will describe (i) a novel experimental design to understand how these transitions happen and (ii) a novel application of functional data analysis to help farmers breed more synchronised crops. To understand the biological regulation that leads to these transition points, a high temporal resolution of sampling would be required\DSEMIC however, the degree of developmental asynchrony makes such an experiment difficult to design. Instead, we sample a large collection of individual plants at the transition point and then estimate their age retroactively with a bootstrapping strategy, enabling us to order the plants along a pseudotime, giving us an unprecedented level of detail of the cascade of biological events that lead to the initiation of flowering. We then hypothesised that plants that are more sensitive to changes in day length (as occur in the spring and autumn) would have more synchronised development. Using functional data analysis approaches, we developed a predictive model of flowering synchrony on the basis of how the circadian rhythms of plants respond to changes in day length, in a population of plants with parents adapted from different latitudes. We are further adapting FDA methods to identify genetic loci that are significantly associated with these clock-related traits, which can be used to direct crop breeding for synchronised development. Keywords: |
regular seminar Shubham Gupta (Imperial College London)
at: 01:00 - 01:00 KCL, Strand room: S5.20 abstract: | In the Euclidean space setting, symmetrization inequalities is a classical theory that has been quite useful in solving problems coming from various parts of analysis: spectral geometry, variational problems, mathematical physics, spectral theory, to name a few. In my talk, I will discuss a possible extensions of this theory to the setting of graphs. It is a fairly new topic and most of the results in the area are proved in the last two years. I will talk about these developments, connections of this theory with discrete isoperimetric inequalities, and its possible applications to problems concerning 'analysis on graphs'. The talk will be at the interface of discrete math and analysis, and will be based on a joint work with Stefan Steinerberger. Keywords: |
Regular Seminar Balt van Rees (Ecole Polytechnique)
at: 01:00 - 01:00 KCL Strand room: S0.12 abstract: | The boundary correlation functions for a quantum field theory (QFT) in a fixed anti–de Sitter (AdS) background should reduce to S-matrix elements in the flat-space limit. We consider this procedure in detail for four-point functions. With minimal assumptions we rigorously show that the resulting S-matrix element obeys a dispersion relation, the nonlinear unitarity conditions, and the Froissart-Martin bound. QFT in AdS thus provides an alternative route to fundamental QFT results that normally rely on the LSZ axioms. Keywords: |
regular seminar Dr Asuka Kumon (King's College London)
at: 01:00 - 01:00 KCL, Strand room: K0.50 abstract: | Keywords: Outreach |
regular seminar Albert Wood (King's College London)
at: 01:00 - 01:00 KCL, Strand room: S4.29 abstract: | Mean Curvature Flow, the negative gradient flow for the volume functional of submanifolds of Riemannian manifolds, is a well-studied field of modern geometric analysis. Of particular interest are classifications of self-similar solutions (shrinkers, expanders, and translators) and finite-time singularities\DSEMIC projects which when completed will hopefully allow one to apply the flow to prove results in Riemannian geometry and differential topology. Moreover, in a Calabi-Yau manifold the class of Lagrangian submanifolds is preserved by mean curvature flow, a fact which inspired Thomas and Yau to make influential conjectures about existence of special Lagrangians in Calabi-Yau manifolds.
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regular seminar Ilya Pavlyukevich (Friedrich Schiller University Jena)
at: 01:00 - 01:00 KCL, Strand room: Strand Building S4.29 abstract: | We study solutions of the irregular Stratonovich SDE $dX = X|^\alpha \circ dB$, $\alpha\in (0, 1)$. In particular we construct solutions spending positive time in 0, describe solutions spending zero time in 0, and show how a particular physically natural solution can be singled out by means of an additional external "ambient" noise.
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regular seminar Sam Power (University of Bristol)
at: 01:00 - 01:00 KCL, Strand room: Strand Building S4.29 abstract: | The Random Walk Metropolis (RWM) is a simple and enduring Markov chain-based algorithm for approximate simulation from an intractable ‘target’ probability distribution. In this work, we study quantitatively the convergence of this algorithm, providing non-asymptotic estimates on mixing times, with explicit dependence on dimension and other problem parameters. The results hold at a reasonable level of generality, and are often sharp in a suitable sense.
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at: 01:00 - 01:00 KCL, Strand room: S4.23 abstract: | second lecture by Prof Leonid A. Pastur
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journal club Pardo Santos Diego (KCL)
at: 01:00 - 01:00 KCL, Strand room: Norfolk Building 342N abstract: | The non-minimal coupling of scalar fields to gravity has been claimed to violate energy conditions,
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regular seminar Shubham Gupta (Imperial College London)
at: 01:00 - 01:00 KCL, Strand room: S4.29 abstract: | In the Euclidean space setting, symmetrization inequalities is a classical theory that has been quite useful in solving problems coming from various parts of analysis: spectral geometry, variational problems, mathematical physics, spectral theory, to name a few. In my talk, I will discuss a possible extensions of this theory to the setting of graphs. It is a fairly new topic and most of the results in the area are proved in the last two years. I will talk about these developments, connections of this theory with discrete isoperimetric inequalities, and its possible applications to problems concerning 'analysis on graphs'. The talk will be at the interface of discrete math and analysis, and will be based on a joint work with Stefan Steinerberger. Keywords: |
Regular Seminar Marco Meineri (U. Turin)
at: 01:00 - 01:00 KCL Strand room: S0.12 abstract: | We consider the renormalization group flow of a quantum field theory (QFT) in Anti-de Sitter (AdS) space. We derive sum rules that express UV data and the energy of a chosen eigenstate in terms of the spectral densities and certain correlation functions of the theory. In two dimensions, this leads to a bootstrap setup that involves the UV central charge and may allow us to follow a Renormalization Group (RG) flow non-perturbatively by continuously varying the AdS radius. Along the way, we establish the convergence properties of the newly discovered local block decomposition, which applies to three-point functions involving one bulk and two boundary operators. Keywords: |
regular seminar Marco Meineri (U. Turin)
at: 01:00 - 01:00 KCL, Strand room: S0.12 abstract: | Keywords: |
regular seminar Sebastián Velazquez (King's College London)
at: 01:00 - 01:00 KCL, Strand room: S2.29 abstract: | We will review some general concepts of deformation theory. Then we will apply these ideas in order to explore the geometry of the moduli space Inv of foliations on a given variety $X$ around the points corresponding to foliations induced by Lie group actions. More precisely, let $X$ be a smooth projective variety over the complex numbers and $S(d)$ the scheme parametrizing $d$-dimensional Lie subalgebras of $H^0(X,\mathcal{T} X)$. For every $\mathfrak{g} \in S(d)$ one can consider the corresponding element $\mathcal{F}(\mathfrak{g})\in Inv$, whose generic leaf coincides with an orbit of the action of $\exp(\mathfrak{g})$ on $X$. We will show that under mild hypotheses, after taking a stratification $\coprod_i S(d)_i\to S(d)$ this assignment yields an isomorphism $\coprod_i S(d)_i\to Inv$ locally around $\mathfrak{g}$ and $\mathcal{F}(\mathfrak{g})$. Keywords: |
regular seminar Markus Riedle (King's College London)
at: 01:00 - 01:00 KCL, Strand room: Strand Building S4.29 abstract: | Cylindrical Lévy processes are a natural extension of cylindrical Brownian motion which has been the standard model of random perturbations of partial differential equations and other models in infinite dimensions for the last 50 years. Here, the attribute cylindrical refers to the fact that cylindrical Brownian motions are not classical stochastic processes attaining values in the underlying space but are generalised objects. The reasons for the choice of cylindrical but not classical Brownian motion can be found in the facts that there does not exist a classical Brownian motion with independent components in an infinite dimensional Hilbert space, and that cylindrical processes enable a very flexible modelling of random noise in time and space.
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journal club Pethybridge Ben ()
at: 01:00 - 01:00 KCL, Strand room: Norfolk Building 342N abstract: | Keywords: |
regular seminar Judith Rousseau (University of Oxford)
at: 01:00 - 01:00 KCL, Strand room: S5.20 abstract: | Multivariate nonlinear Hawkes processes are powerful models for multi-
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at: 01:00 - 01:00 KCL, Strand room: Nash Lecture Theatre K2.31 abstract: | The Disordered Systems Group at King's College London is organising a two-day event on the physics of disorder in both the classical and quantum setting, hosting a selection of international leading experts in the field. The first day of the event will be dedicated to our dear colleague Reimer Kühn, who is retiring at the end of the current academic year. The Workshop will be an opportunity to thank Reimer for his invaluable contributions to the field and to the life of our research group. More infos at https://disorderdayskcl.weebly.com/ Keywords: |
regular seminar Flavio Nicoletti (Sapienza University of Rome)
at: 01:00 - 01:00 KCL, Strand room: S3.31 abstract: | In recent years, great efforts have been devoted to the study of the vibrational spectrum of glasses [1]. Extensive numerical data show that the density of states of several different glassy models follows a quartic law at low frequencies, with related modes spatially quasi-localised. These observations are consistent with predictions of pre-existing phenomenological theories, like the soft potential model [2], in which a glass is effectively represented as a set of interacting anharmonic oscillators.
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regular seminar Stefan Geiss (University of Jyväskylä (Finland) )
at: 01:00 - 01:00 KCL, Strand room: abstract: | Assume a pure jump L\'evy process $X=(X_t)_{t\in [0,T]}$ with L\'evy measure $\nu$ and a Borel function $f:\rm{\bf R} \to \rm{\bf R}$ with $f(x+X_s)\in L_1$ for $(s,x)\in [0,T]\times \rm{\bf R}$. Define $F:[0,T]\times \rm{\bf R}\to \rm{\bf R}$ by
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