Gravity on large scales is relatively well understood. For galaxies, planets and apples: we have Einstein’s General Relativity with which to make accurate predictions. But on small scales, where quantum mechanics becomes important, gravity is more difficult to understand, and as a result we lack precise descriptions of various natural phenomena (such as black holes).
One way to make progress in in our search for quantum gravity is to start from the large scale theory we know and love (at the ‘bottom’), and look for ways in which it may be modified and improved as we zoom in to smaller scales (going ‘up’ to a more fundamental theory).
Recent progress in ‘Effective Field Theory’ may shed some light on the connections between large and small scale physics. By exploiting certain physical properties of scattering probabilities (e.g. that they are unitary, causal and local), one can derive an infinite number of constraints which any large scale theory must satisfy in order to admit a sensible small scale completion.
In this talk, I will provide an overview of these new ‘positivity constraints’, and discuss their implications for quantum gravity.
OIST Workshop - Application Deadline: Feb 15, 2018 - OIST members are welcome to attend all scientific sessions - Website: https://groups.oist.jp/grad/collaborative-experimental-design-and-analytics-ceda-2018
Online registration required.
Welcome Ceremony for Class of 2018 New Students
[Seminar] "Fluctuating gravitational field as a possible explanation for quantum decoherence: its implication and detection" by Dr. Sayantani BeraTuesday, September 4, 2018 - 15:00 to 16:00
The theory of quantum mechanics, despite being highly successful, is plagued with foundational issues such as the “measurement problem”. Understanding the process of “measurement” and the random collapse of the wavefunction
s from a more profound perspective than the standard Copenhagen picture has been one of the major aims in foundational quantum mechanics. Many alternative explanations such as Bohmian mechanics, Continuous Spontaneous Localization model (CSL), many-worlds interpretation etc. have been suggested to address the issue. Possibilities that the wavefunction collapse is a manifestation of the non-standard coupling of the quantum particles with the background gravitational field have also been explored in this context. Such an interpretation does not alter the theory of quantum mechanics, but relates the quantum theory with the background geometry in order to seek for an answer to the long-standing problem. The possibility that the background fluctuating spacetime plays an important role in quantum decoherence has been explored in great details by Karolyhazy, Diosi and collaborators, and also by Penrose. In this talk, I will discuss the physics involved in such ideas, elaborating on the differences between different models. I will also talk about some important implications of such models, their lack of completeness, and possible ways to address the issues. I will discuss the so called “Diosi-Penrose” criterion (independently suggested by Diosi and Penrose), which might be an indication of a universal scale at which the interplay of gravity and quantum mechanics becomes important. Lastly, I will briefly talk about scenarios where such effects can be experimentally detected and the technical challenges involved.
During this workshop participants will learn the foundation of project management and how to develop project management tools based on their personal strengths.
TO REGISTER CLICK HERE
Online registration is required (except new students).
Come and join a lively discussion with successful Japanese and non-Japanese grant recipients.
EVERYONE IS WELCOME!
[Seminar] "Developmental Robotics for Language Learning, Trust and Theory of Mind" by Prof. Angelo CangelosiFriday, September 21, 2018 - 16:00 to 17:00
"Developmental Robotics for Language Learning, Trust and Theory of Mind" by Prof. Angelo Cangelosi, University of Manchester and University of Plymouth