Since 2002 Perimeter Institute has been recording seminars, conference talks, public outreach events such as talks from top scientists using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities.
Recordings of events in these areas are all available and On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
Accessibly by anyone with internet, Perimeter aims to share the power and wonder of science with this free library.
Last year strong evidence was
claimed for a 130 GeV gamma ray line from the galactic center in the FERMI
telescope data. In the first half of the talk I will review the status of
the evidence, including recent suggestions which call it into question.
In the second half of the talk, under the bold assumption that the line
is a genuine signature of dark matter, I will review some of the properties
required of dark matter to explain the line and the general features of models
Newton’s inferences from phenomena realize an ideal of
empirical success that’s richer than prediction. To realize Newton’s richer
conception of empirical success a theory needs to do more than to accurately
predict the phenomena it purports to explain: in addition it needs to have the
phenomena accurately measure parameters of the theory. Newton’s method aims to
turn theoretical questions into ones which can be empirically answered by
measurements from phenomena.
A mixed state can be expressed as a sum of D tensor product matrices, where D is its operator Schmidt rank, or as the result of a purification with a purifying state of Schmidt rank D', where D' is its purification rank. The question whether D' can be upper bounded by D is important theoretically (to establish a description of mixed states with tensor networks), as well as numerically (as the first decomposition is more efficient, but the second one guarantees positive-semidefiniteness after truncation).
In the last few years there has been a burst of
progress in the field of massive gravity. The construction of consistent
theories in which the graviton has a small mass has in turn led to the
development a new family of compelling, consistent low-energy modifications of
General Relativity. These theories improve our understanding of the
interplay between gravity and particle physics and provide new approaches to
solving the cosmological constant problem. In this talk I will review
Check back for details on the next lecture in Perimeter's Public Lectures Series