• Analytic structure of nonhydrodynamic modes in kinetic theory 

      Kurkela, Aleksi; Wiedemann, Urs Achim (Peer reviewed; Journal article, 2019-09)
      How physical systems approach hydrodynamic behavior is governed by the decay of nonhydrodynamic modes. Here, we start from a relativistic kinetic theory that encodes relaxation mechanisms governed by different timescales ...
    • Chemical equilibration in hadronic collisions 

      Kurkela, Aleksi; Mazeliauskas, Aleksas (Peer reviewed; Journal article, 2019)
      We study chemical equilibration in out-of-equilibrium quark-gluon plasma using the first principles method of QCD effective kinetic theory, accurate at weak coupling. In longitudinally expanding systems—relevant for ...
    • Chemical equilibration in weakly coupled QCD 

      Kurkela, Aleksi; Mazeliauskas, Aleksas (Peer reviewed; Journal article, 2019)
      We study thermalization, hydrodynamization, and chemical equilibration in out-of-equilibrium quark-gluon plasma starting from various initial conditions using QCD effective kinetic theory, valid at weak coupling. In ...
    • Early- and Late-Time Behavior of Attractors in Heavy-Ion Collisions 

      Kurkela, Aleksi; van der Schee, Wilke; Wiedemann, Urs Achim; Wu, Bin (Peer reviewed; Journal article, 2020)
      Whether, how, and to what extent solutions of Bjorken-expanding systems become insensitive to aspects of their initial conditions is of importance for heavy-ion collisions. Here we study 1+1D and phenomenologically relevant ...
    • Effective kinetic description of event-by-event pre-equilibrium dynamics in high-energy heavy-ion collisions 

      Kurkela, Aleksi; Mazeliauskas, Aleksas; Paquet, Jean-Francois; Schlichting, Sören; Teaney, Derek (Peer reviewed; Journal article, 2019)
      We develop a macroscopic description of the space-time evolution of the energy-momentum tensor during the pre-equilibrium stage of a high-energy heavy-ion collision. Based on a weak coupling effective kinetic description ...
    • Evidence for quark-matter cores in massive neutron stars 

      Annala, Eemeli; Gorda, Tyler; Kurkela, Aleksi; Nättilä, Joonas; Vuorinen, Aleksi (Peer reviewed; Journal article, 2020-06)
      The theory governing the strong nuclear force—quantum chromodynamics—predicts that at sufficiently high energy densities, hadronic nuclear matter undergoes a deconfinement transition to a new phase of quarks and gluons1. ...
    • Flow in AA and pA as an interplay of fluid-like and non-fluid like excitations 

      Kurkela, Aleksi; Wiedemann, Urs Achim; Wu, Bin (Peer reviewed; Journal article, 2019)
      To study the microscopic structure of quark–gluon plasma, data from hadronic collisions must be confronted with models that go beyond fluid dynamics. Here, we study a simple kinetic theory model that encompasses fluid ...
    • Heavy quark diffusion in an overoccupied gluon plasma 

      Boguslavski, Kirill; Kurkela, Aleksi; Lappi, Tuomas; Peuron, Jarkko (Peer reviewed; Journal article, 2020-09)
      We extract the heavy-quark diffusion coefficient κ and the resulting momentum broadening 〈p2〉 in a far-from-equilibrium non-Abelian plasma. We find several features in the time dependence of the momentum broadening: a short ...
    • Highly occupied gauge theories in 2+1 dimensions: A self-similar attractor 

      Boguslavski, K; Kurkela, Aleksi; Lappi, T; Peuron, J (Peer reviewed; Journal article, 2019-11)
      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 ...
    • Matching the Nonequilibrium Initial Stage of Heavy Ion Collisions to Hydrodynamics with QCD Kinetic Theory 

      Kurkela, Aleksi; Mazeliauskas, Aleksas; Paquet, Jean-Francois; Schlichting, Sören; Teaney, Derek (Peer reviewed; Journal article, 2019-03)
      High-energy nuclear collisions produce a nonequilibrium plasma of quarks and gluons which thermalizes and exhibits hydrodynamic flow. There are currently no practical frameworks to connect the early particle production in ...
    • Nonequilibrium attractor in high-temperature QCD plasmas 

      Almaalol, Dekrayat; Kurkela, Aleksi; Strickland, Michael (Peer reviewed; Journal article, 2020)
      We establish the existence of a far-from-equilibrium attractor in weakly coupled gauge theory undergoing one-dimensional Bjorken expansion. We demonstrate that the resulting far-from-equilibrium evolution is insensitive ...
    • On high-order perturbative calculations at finite density 

      Ghisoiu, Ioan; Gorda, Tyler; Kurkela, Aleksi; Romatschke, Paul; Säppi, Matias; Vuorinen, Aleksi (Journal article; Peer reviewed, 2017-02)
      We discuss the prospects of performing high-order perturbative calculations in systems characterized by a vanishing temperature but finite density. In particular, we show that the determination of generic Feynman integrals ...
    • Opacity dependence of elliptic flow in kinetic theory 

      Kurkela, Aleksi; Wiedemann, Urs Achim; Wu, Bin (Peer reviewed; Journal article, 2019-09)
      The observation of large azimuthal anisotropies vn in the particle spectra of proton–proton (pp) and proton–nucleus (pA) collisions challenges fluid dynamic interpretations of vn, as it remains unclear how small collision ...
    • Perturbative thermal QCD: Formalism and applications 

      Ghiglieri, Jacopo; Kurkela, Aleksi; Strickland, Michael; Vuorinen, Aleksi (Peer reviewed; Journal article, 2020)
      In this review article, we discuss the current status and future prospects of perturbation theory as a means of studying the equilibrium thermodynamic and near-equilibrium transport properties of deconfined QCD matter. We ...
    • Predicting parton energy loss in small collision systems 

      Huss, Alexander; Kurkela, Aleksi; Mazeliauskas, Aleksas; Paatelainen, Risto; van der Schee, Wilke; Wiedemann, Urs Achim (Peer reviewed; Journal article, 2021)
      Medium induced parton energy loss is not conclusively established either in very peripheral heavy-ion collisions or in proton-ion collisions. However, the standard interpretation of azimuthal momentum anisotropies in these ...
    • Quantum chromodynamics and particle energy-loss in heavy-ion collisions due to medium interactions. 

      Kjærnsmo, Amanda Lavinia (Master thesis, 2021)
      This study is following a simple model for predicting particle energy-loss due to medium interactions. Observables from heavy-ion collisions suggests the formation of a highly dense medium called quark-gluon plasma (QGP). ...
    • Spectral function for overoccupied gluodynamics from classical lattice simulations 

      Boguslavski, Kirill; Kurkela, Aleksi; Lappi, Tuomas; Peuron, Jarkko (Peer reviewed; Journal article, 2019)
      We study the spectral properties of an overoccupied gluonic system far from equilibrium. Using classical Yang–Mills simulations and linear response theory, we determine the statistical and spectral functions. We measure ...