Theoretical Physics - From Outer Space to Plasma

This talk explains how qubits are used to represent numbers in a way that permits 'quantum-mechanical parallel' computing. We show how this can used to achieve fast factorisation of large numbers, and hence the breaking of current codes. We end by explaining how entangled pairs of particles can be used to provide an alternative and entirely secure cryptographic system.

This talk reviews how to deal with quantum systems that are coupled to the outside world, as in reality all systems are. We first introduce density operators and explain how quantum states give rise to them. We then turn to measures of entanglement that can be computed from a density operator, and show that entanglement grows with time. Finally, we show how the interaction with the environment giv...

This talk reviews the modern formulation of the basic ideas of quantum mechanics. We start by explaining what quantum amplitudes are, how they lead to the idea of a quantum state and how these states evolve in time. We then discuss what happens when a measurement is made before describing correlated ('entangled') systems. Applying these ideas to two-state systems ('qubits') we point out that the c...

Dr Ralph Schoenrich will talk about the chemical evolution side Spiral density waves patterns re-distribute stars throughout the entire system, making it impossible to know a star's origin from just its kinematics. However, stars are more than just points in phase space: every star is labelled with the elemental abundances of the gas cloud from which it was formed. Over the last few years a number...

Dr John Magorrian will talk about the dynamics of galaxy discs In galaxy discs it is energetically favourable for angular momentum to move outwards and mass to move inwards. This transportation is effected by spiral arms, but what causes them? Simple linear response calculations demonstrate that even the smallest perturbation is amplified manyfold, while the differential rotation of the disc means...

Prof James Binney FRS will talk about stellar systems: a new state of matter The long range of gravity means that many concepts from undergraduate statistical mechanics do not apply: energy is not extensive; there is no microcanonical or canonical ensemble. Stars and dark matter particles have long mean free paths, which means that to a very good approximation their motion is determined by the mea...

In this talk, Siddharth Parameswaran discusses how a topological approach to 2D systems reveal that they can indeed become superfluid, and lead to surprising and beautiful universal results whose implications continue to resonate today. Superfluids spontaneously break a continuous symmetry linked to the conservation of particle number in a many-body system. Standard lore holds that such symmetries...

Stephen Blundell reviews a theory of superconductivity that was developed in Oxford in the 1930’s by Fritz London. The idea is that under certain conditions quantum coherent effects can become manifest on a large scale. In an effect such as superconductivity, this idea can be put to use in such applications as magnetic resonance imaging, in which a living human patient is inserted inside a quantum...

John Chalker discusses how the laws of quantum mechanics lead us from the microscopic world to macroscopic phenomena. The notion that atoms of a given isotope are indistinguishable has profound consequences in the quantum world. For liquids made of identical bosons, indistinguishability forces the particles into a quantum condensate at low temperature, where they all dance in perfect synchrony. Tr...

John March-Russell gives a talk about gravitational wave signals of stringy physics, a ‘soundscape’ connected to the landscape of string vacua.

Subir Sarkar reviews the detection of the ‘chirrup’ signal from a pair of merging massive black holes by the Laser Interferometer Gravitational-Wave Observatory, as well as subsequent experimental developments.

James Binney gives a talk about the mathematics that describe Gravitational waves.

Fasten Your Seat Belts: Turbulent Flows in Nature. Turbulence is ubiquitous in nature, and it often causes us headaches both literal and metaphorical. From unpredictable weather to the mixing of milk in our coffee, Michael Barnes will talk about how turbulence arises and our ongoing struggle to control it.

Ramin Golestanian will introduce you to Life at Low Reynolds number and ask how microorganisms can swim, navigate, and coordinate their activities. You will discover how the left-right symmetry is first broken in a developing embryo, and investigate the medically important question of how mucus is shifted in our lungs and what happens when things go wrong.

Julia Yeomans will talk about fluids and flows all around us: from superhydrophobic surfaces and how animals and plants keep dry, to bouncing droplets and balloons.

Third lecture "More is different" - how states of matter emerge from quantum theory Saturday morning of Theoretical Physics. With Professor Steve Simon, introduction by Professor John WheelerThird Steve Simon will focus on the recent realization that Landau’s classification, thought to be complete for most of the twentieth century, in fact misses some of the most exciting, yet subtle, physics. The...

Second lecture "More is different" - how states of matter emerge from quantum theory Saturday morning of Theoretical Physics. With Professor Fabian Essler, introduction by Professor John Wheeler. Fabian Essler will discuss the hugely successful framework for classifying possible states of quantum matter, pioneered by the great Russian Nobel Laureate, Lev Landau. This framework is conceptually rema...

First lecture in the "More is different" - how states of matter emerge from quantum theory Saturday morning of Theoretical Physics. With Professor John Chalker, introduction by Professor John Wheeler. John Chalker will review the quantum mechanics of identical particles which forms the foundation for our understanding of why diamond is transparent and why gold conducts electricity. He will also ex...

Members of the Rudolf Peierls Centre for Theoretical Physics hosted the ninth Saturday Morning of Theoretical Physics on 21st May 2016. Talk 3 by Dr Andrei Starinets.

Members of the Rudolf Peierls Centre for Theoretical Physics hosted the ninth Saturday Morning of Theoretical Physics on 21st May 2016. Talk 2 by Professor Andre Lukas.

Members of the Rudolf Peierls Centre for Theoretical Physics hosted the ninth Saturday Morning of Theoretical Physics on 21st May 2016. Talk 1 by Professor Joseph Conlon.

The power of available computers has now grown exponentially for many decades. The ability to discover numerically the implications of equations and models has opened our eyes to previously hidden aspects of physics. Many exciting phenomena observed in condensed matter systems, such as superconductivity and the quantum Hall effect, emerge due to the quantum mechanical interplay of many electrons....

The power of available computers has now grown exponentially for many decades. The ability to discover numerically the implications of equations and models has opened our eyes to previously hidden aspects of physics. In physics, "complex systems" are systems of many similar interacting parts, such as the interacting atoms that make up a solid or liquid, but also interacting organisms in an ecosyst...

The power of available computers has now grown exponentially for many decades. The ability to discover numerically the implications of equations and models has opened our eyes to previously hidden aspects of physics. In this lecture, Myles Allen addressed how computers have transformed our understanding of the role of chaos and exponential error growth in weather forecasting; and our understanding...

Members of the Rudolf Peierls Centre for Theoretical Physics hosted the eighth Saturday Morning of Theoretical Physics on 19 September 2015. Talk 3 by Professor James Binney.