This series covers all areas of research at Perimeter Institute, as well as those outside of PI's scope.
The Hubble constant remains one of the most important parameters in the cosmological model, setting the size and age scales of the Universe. Present uncertainties in the cosmological model including the nature of dark energy, the properties of neutrinos and the scale of departures from flat geometry can be constrained by measurements of the Hubble constant made to higher precision than was possible with the first generations of Hubble Telescope instruments.
Computing has had many fundamental platform shifts in its history, and each came shrouded with mystery, hype, and dazzling potential: Alan Turing's universal machines, Doug Engelbart's Dynamic Knowledge Repository, J.C.R. Licklider's Intergalactic Network, the development of the internet, and all the waves of personal computers. More recently, Web 1.0, Web 2.0, and now Web 3.0 have all been heralded with barely-working demos and baffling hype, only to quietly install and broadly distribute fundamental improvements to our everyday life, to our work, and to our society.
Embezzlement of entanglement is the (impossible) task of producing an entangled state from a product state via a local change of basis, when a suitable catalytic entangled state is available. The possibility to approximate this task was first observed by van Dam and Hayden in 2002. Since then, the phenomenon is found to play crucial roles in many aspects of quantum information theory. In this colloquium, we will explain various methods to embezzlement entanglement and explore applications (such as an extension to approximately violate other conservation laws, a Bell inequality that canno
Einstein is well known for his rejection of quantum mechanics in the form it emerged from the work of Heisenberg, Born and Schrodinger in 1926. Much less appreciated are the many seminal contributions he made to quantum theory prior to his final scientific verdict: that the theory was at best incomplete. In this talk I present an overview of Einstein’s many conceptual breakthroughs and place them in historical context. I argue that Einstein, much more than Planck, introduced the concept of quantization of energy in atomic mechanics.
Gauge theories are fundamental to our understanding of interactions between the elementary constituents of matter as mediated by gauge bosons. However, computing the real-time dynamics in gauge theories is a notorious challenge for classical computational methods. In the spirit of Feynman's vision of a quantum simulator, this has recently stimulated theoretical effort to devise schemes for simulating such theories on engineered quantum-mechanical devices, with the difficulty that gauge invariance and the associated local conservation laws (Gauss laws) need to be implemented.
The study of strongly interacting quantum matter has been at the forefront of condensed matter research in the last several decades. An independent development is the discovery of topological band insulators. In this talk I will describe phenomena that occur at the confluence of topology and strong interactions.
Over the years, many rich ideas have been exchanged between particle theory and condensed matter theory, such as particle/hole theory, superconductivity and dynamical symmetry breaking, universality and critical phenomena.
In some of the planet's most extreme environments scientists are constructing enormous detectors to study the very rare interactions produced by neutrinos. In particular, at South Pole Station Antarctica more than a cubic kilometer of the deep glacial ice has been instrumented to construct the world's largest neutrino detector to date: the IceCube Neutrino Observatory.
Despite intensive theoretical research for several decades, the theory of quantum gravity remains elusive. I will review the obstacles that prevent from reconciling the principles of general relativity with those of quantum mechanics. It is plausible that an eventual ultraviolet completion of general relativity will require sacrificing some of these principles. I will then focus on the class of theories where the abandoned property is local Lorentz invariance, replaced by an approximate anisotropic scaling symmetry in deep ultraviolet.
Hidden sector particles, with masses and couplings below those of the weak interactions, can resolve many of the outstanding questions of the Standard Model, including the identity of dark matter, the origin of the baryon asymmetry, and the physics of neutrino masses. Existing searches at colliders such as the Large Hadron Collider are, however, often insensitive to signals of hidden sectors. Using the well-motivated example of low-scale leptogenesis and neutrino masses, I will demonstrate connections between the cosmology of hidden sectors and their signatures in experiments.