This series covers all areas of research at Perimeter Institute, as well as those outside of PI's scope.
Cosmic inflation has given us a remarkably successful cosmological phenomenology. But the original goal of explaining why the cosmos is *likely* to take the form we observe has proven very difficult to realize. I review the status of "eternal inflation" with an eye on the roles various infinities have (both helpful and unhelpful) in our current understanding. I then discuss attempts to construct an alternative cosmological framework that is truly finite, using ideas about equilibrium and dark energy. I report some recent results that point to observable signatures.
Hubeny identified a scenario in which a charged particle falling toward a near-extreme Reissner-Nordstrom black hole can penetrate the black hole and drive it beyond the extremal limit, thereby giving rise to an apparent violation of cosmic censorship. A version of this scenario, relevant to a Kerr black hole and involving a particle with orbital and/or spin angular momentum, was recently examined by Jacobson and Sotiriou (following up on earlier work by Hod); here also the black hole is driven beyond the extremal limit.
In my talk I raise the question of the fundamental limits to the size of thermal machines - refrigerators, heat pumps and work producing engines - and I will present the smallest possible ones. I will also discuss the issue of a possible complementarity between size and efficiency and show that even the smallest machines could be maximally efficient. Finally I will present a new point of view over what is work and what do thermal machines actually do.
The quantum mechanical state vector is a complicated object. In particular, the amount of data that must be given in order to specify the state vector (even approximately) increases exponentially with the number of quantum systems. Does this mean that the universe is, in some sense, exponentially complicated? I argue that the answer is yes, if the state vector is a one-to-one description of some part of physical reality. This is the case according to both the Everett and Bohm interpretations.
Sage is a collection of mature open source software for mathematics, and new code, all unified into one powerful and easy-to-use package.
The mission statement of the Sage project is: "Creating a viable free open source alternative to Magma, Maple, Mathematica and Matlab."
More information is available at www.sagemath.org. I will use the Sage notebook (a web interface) to demonstrate the use of Sage for a variety of mathematical problems and comment on its design and future direction.
I will discuss the growth of entanglement under a quantum quench at point contacts of simple fractional quantum Hall fluids and its relation with the measurement of local observables. Recently Klich and Levitov recently proposed that, for a free fermion system, the noise generated from a local quantum quench provides a measure of the entanglement entropy. In this work, I will examine the validity of this proposal in the context of a strongly interacting system, the Laughlin FQH states.
I will describe the current state of our attempts to characterize the nature of the Dark Energy, the name given to the unknown phenomenology that is driving the observed accelerating cosmic expansion. There is a historical analogy between our current situation and the days of
Conformal Field Theory is the language in which we often think about strong dynamics, be that in Condensed Matter, Quantum Gravity, or Beyond the Standard Model Physics. AdS/CFT led to significant advances of our understanding. What should come next?
At the time of recombination, 400,000 years after the Big Bang, the structure of the dark matter distribution was extremely simple and can be inferred directly from observations of structure in the cosmic microwave background. At this time dark matter particles had small thermal velocities and their distribution deviated from uniformity only through a gaussian field of small density fluctuations with associated motions. Later evolution was driven purely by gravity and so obeyed the collisionless Boltzmann equation.