Large-
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>N</mml:mi></mml:math>
 kinetic theory for highly occupied systems

Walz, R.; Boguslavski, Kirill; Berges, Jürgen

doi:10.1103/physrevd.97.116011

Cited by 35 publications

(46 citation statements)

References 72 publications

(318 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nonthermal fixed points have recently also been found experimentally in ultra-cold atom experiments [21,22]. A kinetic theory description of the underlying theory is often a natural way to explain the existence and properties of such fixed points [1,14,[23][24][25][26][27]. These NTFPs appear because the interaction rate of the initial conditions is faster than that of the final equilibrium state.…”

Section: Introductionmentioning

confidence: 94%

Highly occupied gauge theories in 2+1 dimensions: A self-similar attractor

et al. 2019

Self Cite

View full text Add to dashboard Cite

Motivated by the boost-invariant Glasma state in the initial stages in heavy-ion collisions, we perform classical-statistical simulations of SU(2) gauge theory in 2+1 dimensional space-time both with and without a scalar field in the adjoint representation. We show that irrespective of the details of the initial condition, the far-from-equilibrium evolution of these highly occupied systems approaches a unique universal attractor at high momenta that is the same for the gauge and scalar sectors. We extract the scaling exponents and the form of the distribution function close to this non-thermal fixed point. We find that the dynamics are governed by an energy cascade to higher momenta with scaling exponents α = 3β and β = −1/5. We argue that these values can be obtained from parametric estimates within kinetic theory indicating the dominance of small momentum transfer in the scattering processes. We also extract the Debye mass non-perturbatively from a longitudinally polarized correlator and observe an IR enhancement of the scalar correlation function for low momenta below the Debye mass.2 We expect the results to carry over to SU(3) theories as well.The qualitative agreement of weakly-coupled SU(Nc) theories far from equilibrium for Nc = 2, 3 has been observed for different phenomena [31][32][33].arXiv:1907.05892v1 [hep-ph]

show abstract

Section: Introductionmentioning

confidence: 94%

Highly occupied gauge theories in 2+1 dimensions: A self-similar attractor

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…As pointed out in Refs. [4,15,16], the values of these exponents coincide with those of the corresponding non-relativistic scalar model, since infrared momenta below m eff of the relativistic theory behave non-relativistically. Within errors, we also find α = dβ for d = 3 spatial dimensions such that p f (t, |p|) = t α−dβ q f S (|q|) is approximately conserved, reflecting a transport of particles towards lower momenta for the β > 0 observed.…”

Section: A Particle Distributionmentioning

confidence: 55%

“…One observes that in the scaling regime all curves collapse to a single one in the infrared to very good accuracy. In order to illustrate this agreement, we analyze the approximate quasi-particle expression (16). In Fig.…”

Section: B Mode Energymentioning

confidence: 81%

“…A calculation of the far-from-equilibrium scaling exponents and function has so far only been done using additional assumptions, such as a quasi-particle ansatz for an effective kinetic description at the non-thermal fixed point in Refs. [4,15,16], or based on classical-statistical field theory approximations in Ref. [4] in the weak-coupling limit.…”

Section: Universal Scaling Dynamics Of Equal-time Correlationsmentioning

confidence: 99%

“…For a proper quasi-particle description of the energy density one may subtract the zero-mode quantum-half appearing in(16), which we do not consider here for the lattice regularized theory.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Spectral, statistical, and vertex functions in scalar quantum field theory far from equilibrium

Shen

Berges

2020

Phys. Rev. D

View full text Add to dashboard Cite

We compute the far-from-equilibrium dynamics of relativistic scalar quantum fields in 3+1 spacetime dimensions starting from over-occupied initial conditions. We determine universal scaling exponents and functions for two-point correlators and the four-vertex in a self-similar regime in time and space or momenta. The scaling form of the momentum-dependent four-vertex exhibits a dramatic fall-off towards low momenta. Comparing spectral functions (commutators) and statistical correlations (anti-commutators) of field operators allows us to detect strong violations of the fluctuation-dissipation relation in this non-perturbative infrared regime. Based on a self-consistent expansion in the number of field components to next-to-leading order, a wide range of interaction strengths is analyzed and compared to weak-coupling estimates in effective kinetic theory and classical-statistical field theory.

show abstract

Broad excitations in a 2+1D overoccupied gluon plasma

Boguslavski

Kurkela

Lappi

et al. 2021

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

Motivated by the initial stages of high-energy heavy-ion collisions, we study excitations of far-from-equilibrium 2+1 dimensional gauge theories using classical-statistical lattice simulations. We evolve field perturbations over a strongly overoccupied background undergoing self-similar evolution. While in 3+1D the excitations are described by hard-thermal loop theory, their structure in 2+1D is nontrivial and nonperturbative. These nonperturbative interactions lead to broad excitation peaks in spectral and statistical correlation functions. Their width is comparable to the frequency of soft excitations, demonstrating the absence of soft quasiparticles in these theories. Our results also suggest that excitations at higher momenta are sufficiently long-lived, such that an effective kinetic theory description for 2+1 dimensional Glasma-like systems may exist, but its collision kernel must be nonperturbatively determined.

show abstract

Large- N kinetic theory for highly occupied systems

Cited by 35 publications

References 72 publications

Highly occupied gauge theories in 2+1 dimensions: A self-similar attractor

Highly occupied gauge theories in 2+1 dimensions: A self-similar attractor

Spectral, statistical, and vertex functions in scalar quantum field theory far from equilibrium

Broad excitations in a 2+1D overoccupied gluon plasma

Contact Info

Product

Resources

About