Conference/School

Higher algebra has become important throughout mathematics physics and mathematical physics and this conference will bring together leading experts in higher algebra and its mathematical physics applications. In physics the term algebra is used quite broadly any time you can take two operators or fields multiply them and write the answer in some standard form a physicist will be happy to call this an algebra. Higher algebra is characterized by the appearance of a hierarchy of multilinear operations (e.g. A_infty and L_infty algebras). These structures can be higher categorical in nature (e.g. derived categories cosmology theories) and can involve mixtures of operations and co-operations (Hopf algebras Frobenius algebras etc.). Some of these notions are purely algebraic (e.g. algebra objects in a category) while others are quite geometric (e.g. shifted symplectic structures). An early manifestation of higher algebra in high-energy physics was supersymmetry. Supersymmetry makes quantum field theory richer and thus more complicated but at the same time many aspects become more tractable and many problems become exactly solvable. Since then higher algebra has made numerous appearances in mathematical physics both high- and low-energy. A tell-tale sign of the occurrence of higher structures is when classification results involve cohomology. Group cohomology appeared in the classification of condensed matter systems by the results of Wen and collaborators. Altland and Zirnbauer s "ten-fold way" was explained by Kitaev using K-theory. And Kitaev's 16 types of vortex-fermion statistics were classified by spin modular categories. All these results were recently enhanced by the work of Freed and Hopkins based on cobordism theory. In high energy physics cohomology appears most visibly in the form of "anomalies". The Chern--Simons anomaly comes from the fourth cohomology class of a compact Lie group and the 5-brane anomaly is related to a certain cohomology class of the Spin group. The classification of conformal field theories involves the computation of all algebras objects in certain monoidal categories which is a type of non-abelian cohomology. Yet another important role for higher algebra in mathematical physics has been in the famous Langlands duality. Langlands duality began in number theory and then became geometry. It turned into physics when Kapustin and Witten realized geometric Langlands as an electromagnetic duality in cN=4 super Yang--Mills theory. Derived algebra higher categories shifted symplectic geometry cohomology and supersymmetry all appear in Langlands duality. The conference speakers and participants drawn from both sides of the Atlantic and connected by live video streams will explore these myriad aspects of higher algebra in mathematical physics.

The foundations of quantum mechanics have been revitalized in the past few decades by three developments:  (i) the influence of quantum computation and quantum information theory (ii) studies of the interplay between quantum theory and relativity particularly the analysis of indefinite causal structure and (iii) proposals to reconstruct quantum theory from basic axioms.  There have also been very interesting developments in understanding and classifying no=locality and contextuality using tools from sheaf theory and cohomology as well as operator algebras and category theory. The International Congress of Mathematical Physics is a natural forum for the discussion of these topics.  In the past there have been satellite workshops on topics like Operator algebras and quantum statistical mechanics which also address fundamental issues.  The modern study of quantum foundations is very much influenced and informed by mathematics:  sheaf theory and cohomology category theory information theory convex analysis in addition to the continuing interest in operator algebras and functional analysis. The aim of the workshop is to bring together researchers who have made substantial contribution to the recent developments.  The workshop will be held at Perimeter Institute over a five day period from July 30

The 2018 Tri-Institute Summer School on Elementary Particles (TRISEP) will be held July 9-20 2018 in Perimeter Institute for Theoretical Physics Waterloo ON, Canada. TRISEP is an international summer school organized jointly by the Perimeter Institute for Theoretical Physics, SNOLAB, and TRIUMF Canada s laboratory for particle and nuclear physics. TRISEP will feature lectures by leading experts in the field of particle physics in its broadest sense and is designed to be very interactive with ample time for questions, discussions and interaction with the speakers. The school is intended for graduate students of all levels who were already exposed to quantum field theory. For further information, please visit http:///.trisep.ca

Throughout the history of quantum field theory there has been a rich cross-pollination between high energy and condensed matter physics. From the theory of renormalization to the consequences of spontaneous symmetry breaking this interaction has been an incredibly fruitful one. In the last decade there has been a strong resurgence of interest in condensed matter systems in the high energy theoretical physics community. Taking advantage of developments in conformal field theories the conformal bootstrap gauge/gravity and other type of dualities as well as effective field theory techniques high energy theorists with all kinds of specialist backgrounds are thinking about the diverse behavior exhibited in low energy physical systems. Recent developments also employed quantum field theory ideas to improve our understanding of condensed and quantum matter systems as for example Femi liquids strange metals or the behavior of topological defects in ultra cold atom gases. For certain questions such approaches present relevant advantages with respect to more traditional techniques. Moreover in recent years the interplay between high energy and condensed matter physics found new fuel in the search for light dark matter. Indeed theoretical analyses have recently shifted the attention towards model for sub-GeV dark matter. The condensed matter community has played a crucial role in the design of possible new materials and detectors that could allow the observation of such particles. The aim of this workshop is to bring together like-minded high energy theorists with appropriate condensed matter theorists and experimentalists to tackle some of the most interesting problems in modern physics. The format has been designed to allow for plenty of time for open discussion and interaction between the participants. This will reinvigorate existing collaborations as well as create new fruitful ones.

We are entering an exponentially growing phase of gravitational-wave (GW) astronomy excitingly represented by the Nobel Prize in Physics last year - only two years after the first detection. The successful multi-messenger detection of binary neutron star merger in last August has triggered increasing interests to probe the neutron star post-merger gravitational radiations as they will give more decisive and informative description of the post-merger object itself and the GW/electromagnetic emission mechanism. As the post-merger GWs mainly lie in the 1kHz-4kHz band it becomes necessary and important to think about possible third-generation GW detectors that are primarily sensitive to the high frequency band.  In this workshop we shall focus on possible science case and detector configuration for kHz high-frequency detectors. We will have several invited talks while leaving more time for free discussions. We hope this workshop can serve as a seed for much broader discussions in the GW astronomy community and help promote high frequency detectors as one of the development directions of third-generation GW detectors.

The asymptotic safety paradigm is currently emerging as a highly promising idea for Beyond-Standard-Model physics with key progress in asymptotically safe quantum gravity and asymptotically safe matter models. The last years have seen not only the development of asymptotically safe gravity-matter models but also the discovery of asymptotically safe beyond Standard Model matter models that are under control in perturbation theory. New exciting avenues in (astro) particle physics are now waiting to be explored. For example although the nature of dark matter is a long-standing riddle it is a fact that experimental searches have so far not provided any direct clues but have instead come up with ever more stringent constraints on theoretically preferred regions of parameter space for dark-matter-models. Thus the key to unraveling this riddle could be a new theoretical paradigm to guide model builders. This workshop aims at exploring whether asymptotic safety can be a candidate for this new paradigm. We aim to bring together experts on phenomenological models and quantum gravity to probe both the theoretical viability and empirical signatures of asymptotically safe extensions of the standard model that include gravity. To facilitate a highly productive meeting that can trigger new collaborations each talk will be followed up by 15-20 minutes discussion time. Further each day of the workshop will feature a dedicated discussion session. Participants will be encouraged to contribute questions for the discussion both before as well as during the workshop. The last day of the workshop will conclude with a roadmap discussion during which all participants will be given the opportunity to propose concrete suggestions for follow-up work that might lead into future joint projects.

What can you do with a Physics degree?  Plenty although the reality is that most people being trained in physics at the undergraduate graduate or even postdoctoral levels aren't aware of the broad spectrum of opportunities available to them.  The problem solving skills necessary to succeed in physics are sought after in a wide range of technology financial and industrial sectors. This day will bring together current students and postdocs in theoretical physics with former students who have found great success in a wide range of different areas from startups to big companies finance and even bestselling novels.  Many of them were affiliated with Perimeter Institute and chose their career paths over opportunities in academia.  Through a combination of talks and panel sessions this day will showcase the many career possibilities available to young physicists steps they can take to explore these options and how to avoid the inevitable pitfalls. Lunch will be provided and there will ample opportunities to ask questions and network.

Black hole superradiance is a fascinating process in general relativity and a unique window on ultralight particles beyond the standard model. Bosons -- such as axions and dark photons -- with Compton wavelengths comparable to size of astrophysical black holes grow exponentially to form large clouds spinning down the black hole in the process and produce monochromatic continuous gravitational wave radiation. In the era of gravitational wave astronomy and increasingly sensitive observations of astrophysical black holes and their properties superradiance of new light particles is a promising avenue to search for new physics in regimes inaccessible to terrestrial experiments. This workshop will bring together theorists data analysts and observers in particle physics gravitational wave astronomy strong gravity and high energy astrophysics to explore the signatures of black hole superradiance and to study the current and future possibilities of searching for new particles with black holes.

The goal of the workshop is to foster interaction between researchers working on the S-matrices of conventional strings and on ambitwistor strings.  The workshop will exploit synergies between the two frameworks and identify the current key questions in the fields and areas that can benefit from collaboration. The program of the workshop will be tailored to questions and problems raised by the participants in the run-up to the event. The goal is to spend most of the time on collaborative discussions in order to exchange expertise and to attempt to resolve questions during the workshop. A list of such problems can be found below and this will be extended by the participants in the run-up to the meeting. To obtain ambitwistor integrands and Bern-Carrasco-Johansson (BCJ) numerators for multiloop amplitudes and to connect with superstring worldsheet correlators. To develop fully nonlinear approaches by working on curved backgrounds both for application to AdS/CFT and to problems in perturbative gravity and gauge theory on nontrivial backgrounds. To understand the twistor and ambitwistor geometry underpinning both conventional and ambitwistor strings including the geometry of soft limits infrared structure and its links with formulations at null infinity. To explore mathematical structures behind the integrals of conventional and ambitwistor strings (positive geometries and canonical forms twisted (co)-cycle etc.)

Our universe is of astonishing simplicity: almost all physical observations can in principle be described by a few theories that have short mathematical descriptions. But there is a field of computer science which quantifies simplicity namely algorithmic information theory (AIT). In this workshop we will discuss emerging connections between AIT and physics some of which have recently shown up in fields like quantum information theory and thermodynamics. In particular AIT and physics share one goal: namely to predict future observations given previous data. In fact there exists a gold standard of prediction in AIT called Solomonoff induction which is also applied in artificial intelligence. This motivates us to look at a broader question: what is the role of induction in physics? For example can quantum states be understood as Bayesian states of belief? Can physics be understood as a computation in some sense? What is the role of the observer i.e. the agent that is supposed to perform the predictions? These and related topics will be discussed by a diverse group of researchers from different disciplines.