Aspects of the UV/IR correspondence : energy broadening and string fluctuations

Abstract

We show that a source which radiates in the vacuum of the strongly coupled N=4 SYM theory produces an energy distribution which, in the supergravity approximation, has the same space-time pattern as the corresponding classical distribution: the radiation propagates at the speed of light without broadening. We illustrate this on the basis of several examples: a small perturbation propagating down a steady string, a massless particle falling into AdS_5, and the decay of a time-like wave-packet. A similar observation was made in Phys. Rev. D81 (2010) 126001 for the case of a rotating string. In all these cases, the absence of broadening is related to the fact that the energy backreaction on the boundary arises exclusively from the bulk perturbation at, or near, the boundary. This is so since bulk sources which propagate in AdS_5 at the speed of light do not generate any energy on the boundary. We interpret these features as an artifact of the supergravity approximation, which fails to encode quantum mechanical fluctuations that should be present even in the strong coupling limit. We argue that such fluctuations should enter the dual string theory as longitudinal string fluctuations, which are not suppressed at strong coupling. We heuristically estimate the effects of such fluctuations and argue that they restore the broadening of the radiation, in agreement with expectations from both quantum mechanics and the ultraviolet/infrared correspondence.

47 pages

References in corpus (19)

• Energy loss of a heavy quark moving through N=4 supersymmetric Yang-Mills plasma
• Conformal collider physics: Energy and charge correlations
• Drag force in AdS/CFT
• Viscosity, Black Holes, and Quantum Field Theory
• The Pomeron and Gauge/String Duality
• Heavy Quark Diffusion in Strongly Coupled $\mathbb{N}=4$ Yang Mills
• Momentum fluctuations of heavy quarks in the gauge-string duality
• Entropy production in collisions of gravitational shock waves and of heavy ions
• Gluon energy loss in the gauge-string duality
• The wake of a quark moving through a strongly-coupled $\mathcal{N}=4$ supersymmetric Yang-Mills plasma
• The stress-energy tensor of a quark moving through a strongly-coupled N=4 supersymmetric Yang-Mills plasma: comparing hydrodynamics and AdS/CFT
• Comparing energy loss and $p_{\perp }$-broadening in perturbative QCD with strong coupling $\mathcal{N}=4$ SYM theory
• Eikonal Methods in AdS/CFT: Regge Theory and Multi-Reggeon Exchange
• Deep inelastic scattering off a N=4 SYM plasma at strong coupling
• Jets in strongly-coupled N = 4 super Yang-Mills theory
• Nonlinear waves in AdS/CFT correspondence
• Energy disturbances due to a moving quark from gauge-string duality
• Jet fragmentation and gauge/string duality
• Relativistic Beaming in AdS/CFT

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