• Pulsar timing array stochastic background from light Kaluza-Klein resonances 

      Megías, Eugenio; Nardini, Germano; Quirós, Mariano (Peer reviewed; Journal article, 2023-11)
      We investigate the potential of the warped extradimension framework as an explanation for the recently observed stochastic gravitational background at nHz frequencies in pulsar timing arrays (PTA). Our analysis reveals ...
    • Quantum dynamical dissociation of quarkonia by wave function decoherence in quark-gluon plasma 

      Kajimoto, Shiori; Akamatsu, Yukinao; Asakawa, Masayuki; Rothkopf, Alexander Karl (Peer reviewed; Journal article, 2019-02)
      In this study, we investigate the real-time evolution of quarkonium bound states in a quark-gluon plasma in an improved QCD based stochastic potential model. This model describes the quarkonium dynamics in terms of a ...
    • Quantum tunnelling, real-time dynamics and Picard-Lefschetz thimbles 

      Mou, Zonggang; Saffin, Paul M.; Tranberg, Anders (Peer reviewed; Journal article, 2019-11)
      We follow up the work, where in light of the Picard-Lefschetz thimble approach, we split up the real-time path integral into two parts: the initial density matrix part which can be represented via an ensemble of initial ...
    • Quarkonium phenomenology from a generalised Gauss law 

      Lafferty, David; Rothkopf, Alexander Karl (Peer reviewed; Journal article, 2019-05)
      We present an improved analytic parametrisation of the complex in-medium heavy quark potential derived rigorously from the generalised Gauss law. To this end we combine in a self-consistent manner a non-perturbative vacuum ...
    • Quarkonium production and suppression: Theory 

      Rothkopf, Alexander Karl (Peer reviewed; Journal article, 2021-01)
      Heavy quarkonium theory has seen significant progress over the past years. Not only has the community steadily improved the understanding of fully equilibrated quarkonium using first principles lattice QCD studies, but it ...
    • Quarkonium production in the QGP 

      Rothkopf, Alexander Karl (Peer reviewed; Journal article, 2019-05)
      We report on recent theory progress in understanding the production of heavy quarkonium in heavy-ion collisions based on the in-medium heavy-quark potential extracted from lattice QCD simulations. On the one hand, the ...
    • Scattering amplitudes of massive Nambu-Goldstone bosons 

      Brauner, Tomas; Jakobsen, Martin Fonnum (Journal article; Peer reviewed, 2018-01)
      Massive Nambu-Goldstone (mNG) bosons are quasiparticles the gap of which is determined exactly by symmetry. They appear whenever a symmetry is broken spontaneously in the ground state of a quantum many-body system and at ...
    • Simulations of a bubble wall interacting with an electroweak plasma 

      Mou, Zong-Gang; Saffin, Paul M.; Tranberg, Anders (Peer reviewed; Journal article, 2021-02)
      We perform large-scale real-time simulations of a bubble wall sweeping through an out-of-equilibrium plasma. The scenario we have in mind is the electroweak phase transition, which may be first order in extensions of the ...
    • Soft Interactions in Cold Quark Matter 

      Gorda, Tyler; Kurkela, Eero Aleksi; Paatelainen, Risto; Säppi, Saga; Vuorinen, Aleksi (Peer reviewed; Journal article, 2021-10)
      Accurate knowledge of the thermodynamic properties of zero-temperature, high-density quark matter plays an integral role in attempts to constrain the behavior of the dense QCD matter found inside neutron-star cores, ...
    • Stable solvers for real-time Complex Langevin 

      Alvestad, Daniel; Larsen, Rasmus Normann; Rothkopf, Alexander Karl (Peer reviewed; Journal article, 2021-08)
      This study explores the potential of modern implicit solvers for stochastic partial differential equations in the simulation of real-time complex Langevin dynamics. Not only do these methods offer asymptotic stability, ...
    • Statistics on Lefschetz thimbles: Bell/Leggett-Garg inequalities and the classical-statistical approximation 

      Tranberg, Anders; Millington, P; Mou, Zonggang; Saffin, Paul M. (Peer reviewed; Journal article, 2021)
      Inspired by Lefschetz thimble theory, we treat Quantum Field Theory as a statistical theory with a complex Probability Distribution Function (PDF). Such complex-valued PDFs permit the violation of Bell-type inequalities, ...
    • Stochastic inflation from quantum field theory and the parametric dependence of the effective noise amplitude 

      Andersen, Jens Oluf; Tranberg, Anders; Eriksson, Magdalena Britt (Peer reviewed; Journal article, 2022-02)
      The non-linear dynamics of long-wavelength cosmological fluctuations may be phrased in terms of an effective classical, but stochastic evolution equation. The stochastic noise represents short-wavelength modes that continually ...
    • Supernova constraints on dark flavored sectors 

      Camalich, Jorge Martin; Terol-Calvo, Jorge; Tolos Rigueiro, Laura; Ziegler, Robert (Peer reviewed; Journal article, 2021-06)
      Proto-neutron stars forming a few seconds after core-collapse supernovae are hot and dense environments where hyperons can be efficiently produced by weak processes. By making use of various state-of-the-art supernova ...
    • Symmetry and Equivalence in Teleparallel Gravity 

      Coley, Alan; van den Hoogen, Robert; McNutt, David Duncan (Peer reviewed; Journal article, 2020-07)
      In theories such as teleparallel gravity and its extensions, the frame basis replaces the metric tensor as the primary object of study. A choice of coordinate system, frame basis, and spin-connection must be made to obtain ...
    • T3-invariant heterotic Hull-Strominger solutions 

      Svanes, Eirik Eik; Acharya, Bobby S.; Kinsella, Alex (Peer reviewed; Journal article, 2021-01)
      We consider the heterotic string on Calabi-Yau manifolds admitting a Strominger-Yau-Zaslow fibration. Upon reducing the system in the T3-directions, the Hermitian Yang-Mills conditions can then be reinterpreted as a complex ...
    • Thermalization and dynamical spectral properties in the quark-meson model 

      Shen, Lisa; Berges, Jürgen; Pawlowski, Jan M.; Rothkopf, Alexander Karl (Peer reviewed; Journal article, 2020-07)
      We investigate the nonequilibrium evolution of the quark-meson model using two-particle irreducible effective action techniques. Our numerical simulations, which include the full dynamics of the order parameter of chiral ...
    • Thermopower in an anisotropic two-dimensional Weyl semimetal 

      Mandal, Ipsita; Saha, Kush (Journal article, 2020-01)
      We investigate the generation of an electric current from a temperature gradient in a two-dimensional Weyl semimetal with anisotropy in both the presence and absence of a quantizing magnetic field. We show that the anisotropy ...
    • Towards the nucleon hadronic tensor from lattice QCD 

      Liang, Jian; Draper, Terrence; Liu, Keh-Fei; Rothkopf, Alexander Karl; Yang, Yi-Bo (Peer reviewed; Journal article, 2020-06)
      We present the first calculation of the hadronic tensor on the lattice for the nucleon. The hadronic tensor can be used to extract structure functions in deep inelastic scatterings and to provide information for neutrino-nucleon ...
    • Transmission in pseudospin-1 and pseudospin-3/2 semimetals with linear dispersion through scalar and vector potential barriers 

      Mandal, Ipsita (Peer reviewed; Journal article, 2020-09)
      We investigate the tunneling of pseudospin-1 and pseudospin-3/2 quasiparticles through a barrier consisting of both electrostatic and vector potentials, existing uniformly in a finite region along the transmission axis. ...
    • Tunneling in Fermi systems with quadratic band crossing points 

      Mandal, Ipsita (Peer reviewed; Journal article, 2020-08)
      We investigate the tunneling of quasiparticles through a rectangular potential barrier of finite height and width, in 2d and 3d semimetals with band structures consisting of a quadratic band crossing point. We compute the ...