High Energy Physics Seminar next Thursday (Das)

[HECAP - Margherita Di Giovannantonio]

*_HIGH ENERGY PHYSICS SEMINARS_*

/
/
*Thursday, 15* May 2025, at *16:00* - *_L. Stasi seminar room_ **- 
https://indico.ictp.it/event/10999/*
**

*
*


Suman Das  (University of the Witwatersrand)


*“The Simplest Linear Ramp with O(1) Thouless Time **"*
*
*
_Abstract_
Black hole normal modes have intriguing connections to logarithmic 
spectra, and the spectral form factor (SFF) of E_n = log n is the mod 
square of the Riemann zeta function (RZF). In this paper, we first 
provide an analytic understanding of the dip-ramp-plateau structure of 
RZF and show that the ramp at \beta =\Re(s)=0 has a slope precisely 
equal to 1. The s=1 pole of RZF can be viewed as due to a Hagedorn 
transition in this setting, and Riemann's analytic continuation to 
Re(s)< 1 provides the quantum contribution to the truncated log n 
partition function. This perspective yields a precise definition of RZF 
as the ``full ramp after removal of the dip'', and allows an unambiguous 
determination of the Thouless time. For black hole microstates, the 
Thouless time is expected to be O(1)--remarkably, the RZF also exhibits 
this behavior. To our knowledge, this is the first black hole-inspired 
toy model that has a demonstrably O(1) Thouless time. In contrast, it is 
O(log N) in the SYK model and expected to be O(N^{#}) in supergravity 
fuzzballs. We trace the origins of the ramp to a certain reflection 
property of the functional equation satisfied by RZF, and suggest that 
it is a general feature of L-functions--we find evidence for ramps in 
large classes of L-functions. As an aside, we also provide an analytic 
determination of the slopes of (non-linear) ramps that arise in power 
law spectra using Poisson resummation techniques.



To join via Zoom:
https://zoom.us/j/91362325784

Meeting ID: 913 6232 5784

Passcode: 652019