Triangle Seminars
Tuesday, 7 Oct 2025
[Postponed to 18 November] Resurgent symmetry of quantum mirror curves
π South East
Claudia Rella
(IHES)
Abstract:
This seminar will now take place on 18 November
This seminar will now take place on 18 November
Posted by: Γmer GΓΌrdoΔan
Sharp Transitions for Subsystem Complexity
π London
Andreas Karch
(University of Texas)
Abstract:
The circuit complexity of time-evolved pure quantum states
grows linearly in time for an exponentially long time. This behavior has
been proven in certain models, is conjectured to hold for generic
quantum many-body systems, and is believed to be dual to the long-time
growth of black hole interiors in AdS/CFT. Achieving a similar
understanding for mixed states remains an important problem. We
demonstrate that holography predicts several sharp transitions in the
time evolution of subsystem complexity and show that at least some of
these transitions are also realized in random quantum circuits.
The circuit complexity of time-evolved pure quantum states
grows linearly in time for an exponentially long time. This behavior has
been proven in certain models, is conjectured to hold for generic
quantum many-body systems, and is believed to be dual to the long-time
growth of black hole interiors in AdS/CFT. Achieving a similar
understanding for mixed states remains an important problem. We
demonstrate that holography predicts several sharp transitions in the
time evolution of subsystem complexity and show that at least some of
these transitions are also realized in random quantum circuits.
Posted by: Sebastian Cespedes
Wednesday, 8 Oct 2025
An integrable sector for the membrane
π London
David Osten
(U. Wroclaw)
Abstract:
In contrast to string sigma models which are well-known to be (classically) integrable in certain backgrounds, most famously flat space or AdS(5) x S(5), the same is not true for the membrane sigma model. Reasons for this are the non-trivial gravity on the world-volume but also the rarity of three-dimensional integrable field theories in general. Here, I will present the novel observation that a certain decoupling limit of the membrane in certain backgrounds will lead to an integrable model, the Manakov-Zakharov-Ward model – a known three-dimensional, but non-relativistic, integrable field theory. As an example of a supergravity background in which this limit is possible is the 11d uplift of the pure NS-NS AdS(3) x S(3) x T(4) background.
In contrast to string sigma models which are well-known to be (classically) integrable in certain backgrounds, most famously flat space or AdS(5) x S(5), the same is not true for the membrane sigma model. Reasons for this are the non-trivial gravity on the world-volume but also the rarity of three-dimensional integrable field theories in general. Here, I will present the novel observation that a certain decoupling limit of the membrane in certain backgrounds will lead to an integrable model, the Manakov-Zakharov-Ward model – a known three-dimensional, but non-relativistic, integrable field theory. As an example of a supergravity background in which this limit is possible is the 11d uplift of the pure NS-NS AdS(3) x S(3) x T(4) background.
Posted by: Jesse van Muiden
Thursday, 9 Oct 2025
A fresh look at the Froissart bound
π London
Andrea Guerrieri
(City University of London)
Abstract:
The Froissart bound is the most celebrated result of the "analytic S-matrix" program.
It sets an absolute upper limit on total cross-sections at asymptotically high energies in any relativistic quantum theory. In this talk I will discuss an alternative version of this problem and derive rigorous bounds on the cross-section at finite energy, combining analytic techniques and non-perturbative S-matrix bootstrap. I will then discuss the amplitude that saturates our bounds, highlighting its distinctive and rather peculiar properties and connecting them with ancient expectations physicists had on non-perturbative growing amplitudes.
The Froissart bound is the most celebrated result of the "analytic S-matrix" program.
It sets an absolute upper limit on total cross-sections at asymptotically high energies in any relativistic quantum theory. In this talk I will discuss an alternative version of this problem and derive rigorous bounds on the cross-section at finite energy, combining analytic techniques and non-perturbative S-matrix bootstrap. I will then discuss the amplitude that saturates our bounds, highlighting its distinctive and rather peculiar properties and connecting them with ancient expectations physicists had on non-perturbative growing amplitudes.
Posted by: Nathan Moynihan