118407015
On the existence of cosmological event horizons
We show that, for general static or axisymmetric stationary spacetimes, a cosmological Killing horizon exists only if Rabnanb < 0 for a hypersurface orthogonal timelike na, at least over some portion of the region of interest of the manifold. This implies violation of the strong energy condition by the matter fields, the simplest example of which is a positive cosmological constant.
115168470
Generalized vector field
We define generalized vector fields, and contraction and Lie derivatives with respect to them. Generalized commutators are also defined.
119153408
Path Space Forms and Surface Holonomy
We develop parallel transport on path spaces from a differential geometric approach, whose integral version connects with the category theoretic approach. In the framework of 2‐connections, our approach leads to further development of higher gauge theory, where end points of the path need not be fixed.
119451761
A nilpotent symmetry of quantum gauge theories
For the Becchi-Rouet-Stora-Tyutin invariant extended action for any gauge theory, there exists another off-shell nilpotent symmetry. For linear gauges, it can be elevated to a symmetry of the quantum theory and used in the construction of the quantum effective action. Generalizations for nonlinear gauges and actions with higher-order ghost terms are also possible.
119518829
Monopole confinement by flux tube
We revisit Nambu's model of quark confinement by a tube of magnetic flux, with two additional features. The quarks are taken to be magnetic monopoles external to the tube, which seal the ends, and are also taken to be fermions. This ensures that the model is inconsistent unless there are at least two species of fermions being confined.
118864807
Particle with non-Abelian charge: classical and quantum
We study the action for a non-Abelian charged particle in a non-Abelian background field in the worldline formalism, described by real bosonic variables, leading to the well known equations given by Wong. The isospin parts in the action can be viewed as the Lagrange multiplier term corresponding to a non-holonomic constraint restricting the isospins to be parallel transported. The path integration is performed over the isospin variables and as a result, the worldlines turn out to be constrained by the classical solutions for the isospins. We derive a wave equation from the path integral, constructed as the constrained Hamiltonian operator acting on the wave function. The operator ordering corresponding to the quantum Hamiltonian is found and verified by the inverse Weyl transformation.
116271100
Correlation between conserved charges in PNJL Model with multi-quark interactions
We present a study of correlations among conserved charges like baryon number, electric charge and strangeness in the framework of 2+1 flavor Polyakov loop extended Nambu-Jona-Lasinio model at vanishing chemical potentials, up to fourth order. Correlations up to second order have been measured in Lattice QCD which compares well with our estimates given the inherent difference in the pion masses in the two systems. Possible physical implications of these correlations and their importance in understanding the matter obtained in heavy-ion collisions are discussed. We also present comparison of the results with the commonly used unbound effective potential in the quark sector of this model.
117770423
Shear viscosity due to Landau damping from the quark-pion interaction
We have calculated the shear viscosity coefficient $\ensuremath{\eta}$ of the strongly interacting matter in the relaxation time approximation, where a quasiparticle description of quarks with their dynamical masses is considered from the Nambu-Jona-Lasinio model. Due to the thermodynamic scattering of quarks with pseudoscalar-type condensate (i.e., pion), a nonzero Landau damping will be acquired by the propagating quarks. This Landau damping may be obtained from the Landau cut contribution of the in-medium self-energy of a quark-pion loop, which is evaluated in the framework of real-time thermal field theory.