On 't Hooft's S-matrix Ansatz for quantum black holes

Abstract

The S-matrix Ansatz has been proposed by 't Hooft to overcome difficulties and apparent contradictions of standard quantum field theory close to the black hole horizon. In this paper we revisit and explore some of its aspects. We start by computing gravitational backreaction effects on the properties of the Hawking radiation and explain why a more powerful formalism is needed to encode them. We then use the map bulk-boundary fields to investigate the nature of exchange algebras satisfied by operators associated with ingoing and outgoing matter. We propose and comment on some analogies between the non covariant form of the S-matrix amplitude and liquid droplet physics to end up with similarities with string theory amplitudes via an electrostatic analogy. We finally recall the difficulties that one encounters when trying to incorporate non linear gravity effects in 't Hooft's S-matrix and observe how the inclusion of higher order derivatives might help in the black hole microstate counting.

(Non)perturbative gravity, nonlocality, and nice slices

“…While novel, this alternative suggests a picture in accord with observation; moreover, the proposed nonlocality only arises in circumstances of extreme kinematics, and thus would apparently not have been observed elsewhere. The arguments given above share some common elements with discussions of the "S-matrix Ansatz" pursued by 't Hooft and others [43][44][45]. However, there are important differences.…”

“…The arguments given above share some common elements with discussions of the "S-matrix Ansatz" pursued by 't Hooft and others [43][44][45]. However, there are important differences.…”

Production of γγ+2 jets from double parton scattering in proton-proton collisions at the LHC

“…It is independent of the process and of the phase-space under consideration. A number of measurements of σ eff have been performed in pp and pp collisions at √ s=63 GeV [6], 630 GeV [7], 1.8 TeV [8,9,30], 1.96 TeV [10] and also 7 TeV at LHC [3,4]. The measured values range from 5 mb at the lowest energy to about 20 mb from CMS at 7 TeV.…”

“…The higher centreof-mass energy leads to enhanced parton densities, which cause a sizable probability of two or more parton-parton scatterings within the same pp interaction [1,2]. At LHC, various measurements of the differential distributions in W+jets [3,4] and J/ψ+W [5] show that the excesses above the expectations from single parton scattering (SPS) are consistent with double parton scattering (DPS). Various measurements in other pp and pp collisions at √ s=63 GeV [6], 630 GeV [7], and 1.8 TeV [8] are consistent with DPS contributions to multi-jet final states, as well as to γ+3-jet events at √ s=1.8 TeV [9] and 1.96 TeV [10].…”