The 60th birthdays of two major contributors to our present understanding of collective dynamics of hot QCD matter in relativistic heavy-ion collisions are an opportunity for us to look back how this understanding was achieved. Appropriately, I will focus on relativistic kinetic transport theory and fluid dynamics where Dirk and Carsten left their deepest permanent footprints. The talk will...
The quest to determine the nuclear matter equation of state (NMEOS) and its properties has been a central focus of our field for over fifty years. Numerous theoretical predictions regarding the behavior of the NMEOS have motivated major experimental efforts aimed at revealing its properties over a range of densities and temperature. Both Carsten Greiner and Dirk Rischke have made valuable...
We present a systematic method to construct the Shakhov collision term, as an extension of the relaxation time approximation (RTA) of the Boltzmann colllision term ([1]). Our construction is based on the collision matrix in the method of moments and allows an increasing number of first- and second-order transport coefficients to be separately tuned ([2]). The talk is focussed on the...
We compute the moments of the nonlinear binary collision integral in the ultrarelativistic hard-sphere approximation for an arbitrary anisotropic distribution function in the local rest frame. The corresponding moments of the binary collision integral are obtained in terms of quadratic products of different moments of the anisotropic distribution function and couple to a well defined set of...
Utilizing the gravitational Ward identities and gravity-hydrodynamics results, we clarify the analytic structure of all stress-energy correlation functions in the small frequency and the small wave-number limit. From the correlation functions, we obtain several new Kubo formulae for the viscosities. Interestingly, these new Kubo formulae are all obtained with the zero frequency limit taken...
We examine the length scales usually associated with the applicability of hydrodynamics as an effective theory in the light of the observation of hydrodynamic behavior in small systems. We argue that the explanation of such behavior might reside in the requirement of local equivalence between fluctuations and dissipative dynamics. In a way somewhat analogous to the equivalence of gravity...
The last couple of years were the hottest in recorded history, and all climate models under-predicted the severity this global temperature change. These data indicate that exponential feedback loops in Earth's climate are beginning to dominate, eventually causing Earth to become a second Venus. A necessary, but perhaps not sufficient, condition to avoid this catastrophe is to terminate...
Recently, there have been a lot of discussions about the (pseudo-)hydrodynamic theory of spin transport, termed spin hydrodynamics. We discuss its extension to include conformal symmetries, and compare the resultant theory with the known non-relativistic microstretch fluid mechanics.
The spin-1 component of massless gluon will form condensation under rotation thus induce gluon polarization, which can explain the puzzle of enhancement of the phase transition temperature under rotation, and the induced spin alignment of vector mesons is also in agreement with experiment data.
Polarization has opened a new physics chapter in relativistic heavy-ion collisions. Since the first prediction and experimental observation of global spin polarization, a lot of progress has been made in understanding its features, both at experimental and theoretical level. In this talk, I will give a brief overview on the recent advances in this field.
For the past years, different observables related to the spin polarization of hadrons such as $\Lambda$-Baryons have continued to attract attention and pose theoretical challenges.
While some measurements (such as the global polarization) can be reproduced by assuming the spins of the particles to be equilibrated, more differential observables (such as the local polarization) remain a subject...
I will discuss the recent work on the construction of equilibrium hybrid stars, the emergence of twins and triplets, and their signatures, such as mass, radius, and tidal deformability. I will further discuss the bulk viscosity of hybrid star matter, which is relevant for the studies of binary neutron star mergers and their gravitational wave signals.
We present a field-theoretic analysis of neutrino emission from dense quark matter in strong magnetic fields, focusing on conditions relevant to magnetar interiors. In the unpaired quark phase, we study both direct Urca and synchrotron processes. For the Urca process, we develop an approximation that includes Landau quantization for electrons but not quarks, which is appropriate for...
The Nambu–Jona-Lasinio (NJL) model and particularly its extension to color superconductivity is a powerful framework for explorative studies of dense, but not asymptotically dense quark matter. However, its reliability is limited by regularization artifacts that emerge near the cutoff energy scale. Unfortunately, this already affects the phenomenologically most interesting density regime,...
I discuss a remarkable mathematical correspondence between QCD and gravity in Regge asymptotics. We discuss the implications for gravitational radiation, on Black-Hole formation, and in turn back on QCD.
The existence of neutron stars provide us with a challenge and a
possibility to study strong interaction, too. At the center of
neutron stars the densities can reach 6-8 times the normal nuclear
densities, and these densities cannot be studied in terrestrial experiments. Therefore, it provides us with constraints for the properties of the cold, dense strongly interacting matter. The...
I will discuss how the quark-gluon plasma responds to jet propagation in high-energy heavy-ion collisions and what properties of QGP one can learn from these responses. I will also talk about how to measure these responses which amount to very small perturbation of sounds in a hot quark-gluon plasma.
I review work which Captain Dirk and I did on color
superconductivity in the last millennium.
The ambiguity in the choice of the spin tensor has an impact on the description of local thermodynamic equilibrium and, as a consequence, on the theoretical formulae for the spin polarization in relativistic nuclear collisions. In this talk, I will propose a new definition of the local equilibrium density operator which is free of this ambiguity, that is it is pseudo-gauge invariant....
I will discuss research efforts by the Duke QCD group to utilize heavy quarks as probes of the Quark-Gluon-Plasma and extract the heavy-quark transport coefficient of the QGP.
In this talk, I recall the key moments, fundamental steps, and main considerations that led to the construction of the extended Linear Sigma Model. I compare the initial plans for this chiral model of QCD with what has been achieved, and highlight the main contributions to the development of the approach. Selected results for hadrons, both in vacuum and in medium, will also be presented.
