Triangle Seminars
Tuesday, 28 Jan 2020
Table-top Testing of the Non-Classicality of Gravity: A Proposal and its Assumptions, Implications and Practicalities
Sougato Bose
(University College London)
Abstract:
A lack of empirical evidence has lead to a debate on whether gravity is a quantum entity. Motivated by this, I will present a feasible idea for such a test based on the principle that two objects cannot be entangled without a quantum mediator. I will show that despite the weakness of gravity, the phase evolution induced by the gravitational interaction of two micron size test masses in adjacent matter-wave interferometers can detectably entangle them even when they are placed far apart enough to keep Casimir-Polder forces at bay. A prescription for witnessing this entanglement, which certifies gravity as a quantum coherent mediator, is also provided and can be measured through simple spin correlations. Further, I clarify the assumptions underpinning the above proposal such as our reasonable definition of "classicality", as well as the crucial aspect of the locality of physical interactions. The role of off-shell processes is also highlighted. How the experiment sits within relativistic quantum field theory is clarified. Lastly, the practical challenges are noted. Time permitting other applications of superpositions of nano-crystals, such as in sensing classical gravity and how to detect nonclassicalities of such crystals without preparing superpositions at first, will be discussed.
A lack of empirical evidence has lead to a debate on whether gravity is a quantum entity. Motivated by this, I will present a feasible idea for such a test based on the principle that two objects cannot be entangled without a quantum mediator. I will show that despite the weakness of gravity, the phase evolution induced by the gravitational interaction of two micron size test masses in adjacent matter-wave interferometers can detectably entangle them even when they are placed far apart enough to keep Casimir-Polder forces at bay. A prescription for witnessing this entanglement, which certifies gravity as a quantum coherent mediator, is also provided and can be measured through simple spin correlations. Further, I clarify the assumptions underpinning the above proposal such as our reasonable definition of "classicality", as well as the crucial aspect of the locality of physical interactions. The role of off-shell processes is also highlighted. How the experiment sits within relativistic quantum field theory is clarified. Lastly, the practical challenges are noted. Time permitting other applications of superpositions of nano-crystals, such as in sensing classical gravity and how to detect nonclassicalities of such crystals without preparing superpositions at first, will be discussed.
Posted by: IC
TBA
Jacopo de Nardis
(Ghent)
Wednesday, 29 Jan 2020
The O(N) S-matrix monolith
📍 London
Lucia Cordova
(ENS, Paris)
Abstract:
In this talk I will explore the space of two-to-two S-matrices in two-dimensional theories with a global O(N) symmetry, as restricted by the general principles of unitarity, crossing and analyticity. I will describe various features of the allowed space and identify some special points on its boundary with known integrable theories. Finally, I will present a useful dual formulation of the S-matrix bootstrap problem. Based on arXiv:1909.06495.
In this talk I will explore the space of two-to-two S-matrices in two-dimensional theories with a global O(N) symmetry, as restricted by the general principles of unitarity, crossing and analyticity. I will describe various features of the allowed space and identify some special points on its boundary with known integrable theories. Finally, I will present a useful dual formulation of the S-matrix bootstrap problem. Based on arXiv:1909.06495.
Posted by: KCL
Thursday, 30 Jan 2020
TBA
Konstantinos Sfetsos
(University of Athens)
Abstract:
TBA
TBA
Posted by: IC
Non-Hermitian extension of the Standard Model
Jean Alexandre
(King's College)
Abstract:
The work presented here explores the possibility of introducing non-Hermitian scalar and fermion mass terms, in addition to the usual Hermitian ones. The consistency of the resulting description requires a reworking of all the fundamental properties in Field Theory from the beginning, which is challenging but appears to be possible.
The work presented here explores the possibility of introducing non-Hermitian scalar and fermion mass terms, in addition to the usual Hermitian ones. The consistency of the resulting description requires a reworking of all the fundamental properties in Field Theory from the beginning, which is challenging but appears to be possible.
Posted by: QMW