We are located on the Main Campus of City in Northampton Square (map)
Getting to the Strand Campus:
Thea nearest tube stops are Farringdon, Angel, also nearby is Barbican
Farringdon (10 minutes walk) or King's Cross stations (20 minutes walk) have nearest main-line services
Buses stopping outside the College: : 4, 19, 30, 38, 43, 55, 56, 63, 73, 153, 205, 214, 243, 274, 341, 394, 476.
For more information http://www.city.ac.uk/new-students/travel-information.
Found at least 20 result(s)
Regular Seminar Patrick Dorey (Durham)
at: 15:00 room C310 | abstract: This talk will describe some work on the bouncing of particle-like (“kink”) solutions to a nonlinear wave equation, called the sine-Gordon equation, against a fixed boundary. Away from the boundary, this equation has a property known as integrability, making the scattering of the kinks particularly simple. However, if this integrability is broken at the boundary, then the scattering becomes surprisingly complicated, in ways that will be outlined in the talk with the help of some movies. |
Regular Seminar Alexander Altland (Koeln)
at: 15:00 room C310 | abstract: This talk addresses the low energy physics of the Sachdev-Ye-Kitaev model, a paradigm of strongly interacting (Majorana) quantum matter. A salient feature of this system is its exceptionally high degree of symmetry under reparameterizations of physical time. At low energies this symmetry is spontaneously broken and the ensuing infinite dimensional Goldstone mode manifold takes strong influence on all physical observables. We will discuss the effects of these fluctuations on the example of the so-called out of time ordered correlation functions, diagnostic tools to describe both manifestations of quantum chaos in the system and its conjectured duality to an AdS2 gravitational bulk. While previous work predicts exponential decay of these correlations in time our main finding is that at large time scales non-perturbative Goldstone mode fluctuations generate a crossover to power law behavior. This phenomenon must have ramifications in the physics of the holographic bulk which, however, we do not understand at present. |
Regular Seminar Apostolos Vourdas (Bradford)
at: 15:00 room ELG11 | abstract: A total set of states for which we have no resolution of the identity (a 'pre-basis'), is considered in a finite dimensional Hilbert space. A dressing formalism renormalizes them into density matrices which resolve the identity, and makes them a 'generalized basis', which is practically useful. The dresssing mechanism is inspired by Shapley's methodology in cooperative game theory, and it uses Moebius transforms. There is non-independence and redundancy in these generalized bases, which is quantified with a Shannon type of entropy. Due to this redundancy, calculations based on generalized bases, are sensitive to physical changes and robust in the presence of noise. For example, the representation of an arbitrary vector in such generalized bases, is robust when noise is inserted in the coefficients. Also in a physical system with ground state which changes abruptly at some value of the coupling constant, the proposed methodology detects such changes, even when noise is added to the parameters in the Hamiltonian of the system. |
Regular Seminar Sarben Sarkar (King's)
at: 15:00 room ELG04 | abstract: I discuss one and two-parameter solutions of sigma models on symmetric spaces contained in E11. Embedding one-parameter sigma model solutions in space-time give a metric which depends on harmonic functions typical in general relativity, supergravity and M-theory. Embedding two-parameter sigma model solutions in space-time give a metric which depends on general travelling wave functions in M* and M’-theory (theories which have space-time signatures with more than one time). Weyl reflection allows the latter solutions to be mapped to M-theory solutions where the wave functions depend explicitly on extra co-ordinates contained in the fundamental representation of E11. I will also give an example of two-time physics realisable in the laboratory |
Regular Seminar Ran Levi (Aberdeen)
at: 15:00 room ELG08 | abstract: While algebraic topology is now well established as an applicable branch of mathematics, its emergence in neuroscience is surprisingly recent. In this talk I will present a summary of an ongoing joint project with mathematician and neuroscientists. I will start with some basic facts on neuroscience and the digital reconstruction of a rat’s neocortex by the Blue Brain Project in EPFL. I will then explain how data emerging from this reconstruction can be mapped into abstract graphs that in turn give rise to certain mathematical objects in the realm of algebraic and combinatorial topology. Following a short introduction to some of the basic tools of algebraic topology, I will explain how they can potentially be used in the context of neuroscience. Having set up the scene, I will proceed by presenting the results of an ongoing collaboration with the Blue Brain Project team. In particular I shall demonstrate how the topological techniques give new insights on the behaviour of neural systems and inspire new directions in neuroscience research. |
Regular Seminar Christopher Couzens (King's)
at: 11:00 room E205 | abstract: In this talk we consider holographic duals of F-theory solutions to 2d SCFT's. We approach the problem by classifying a particular class of solutions of type IIB supergravity with AdS_3 factors and varying axio-dilaton. The class of solutions we discuss consist of D3 and 7-brane configurations and naturally fall into the realm of F-theory. We prove that for (0,4) supersymmetry in 2d the solutions are essentially unique and we match the holographic central charges to field theory results. We comment on future directions, including AdS_3 solutions of F-theory, preserving different amounts of supersymmetry. |
Colloquium Carlo Rubbia (CERN)
at: 18:30 room Oliver Thompson Lecture Theatre | abstract: "The Role of Elementary Particle Accelerators" http://www.city.ac.uk/events/2017/may/edwards-lecture-the-role-of-elementary-particle-accelerators (Public lecture and Colloquium) |
Regular Seminar Neil Lambert (King's)
at: 15:00 room B103 | abstract: I will discuss some novel algebraic structures and how they lead to the quantum field theories that arise on the world volumes of 2-branes and 5-branes in M-theory. |
Triangular Seminar Kostya Zarembo (NORDITA)
at: 15:00 room A130 | abstract: Quantum fluctuations of the string worldsheet lead to important effects in gauge-string duality. One example is the Lüscher term is the QQ-bar potential in QCD, important for matching the lattice data. I will discuss non-conformal holography of the N=2* theory which provides a controllable setup where the effects of string fluctuations are explicitly calculable in field theory, using localization, even though the problem is intrinsically strongly-coupled. The results obtained by direct quantization of the dual string theory perfectly match the field-theory predictions, after subtle effects like dilaton coupling to the string worldsheet are properly taken into account. |