7 research outputs found
Conformal Field Theory and Geometry of Strings
What is quantum geometry? This question is becoming a popular leitmotiv in
theoretical physics and in mathematics. Conformal field theory may catch a
glimpse of the right answer. We review global aspects of the geometry of
conformal fields, such as duality and mirror symmetry, and interpret them
within Connes' non-commutative geometry. Extended version of lectures given by
the 2nd author at the Mathematical Quantum Theory Conference, Vancouver,
Canada, August 4 to 8, 1993Comment: 44 pages, latex file, 5 references adde
Magnetohydrodynamics of Chiral Relativistic Fluids
We study the dynamics of a plasma of charged relativistic fermions at very
high temperature , where is the fermion mass, coupled to the
electromagnetic field. In particular, we derive a magneto-hydrodynamical
description of the evolution of such a plasma. We show that, as compared to
conventional MHD for a plasma of non-relativistic particles, the hydrodynamical
description of the relativistic plasma involves new degrees of freedom
described by a pseudo-scalar field originating in a local asymmetry in the
densities of left-handed and right-handed fermions. This field can be
interpreted as an effective axion field. Taking into account the chiral anomaly
we present dynamical equations for the evolution of this field, as well as of
other fields appearing in the MHD description of the plasma. Due to its
non-linear coupling to helical magnetic fields, the axion field significantly
affects the dynamics of a magnetized plasma and can give rise to a novel type
of inverse cascade
The turbulent chiral-magnetic cascade in the early universe
The presence of asymmetry between fermions of opposite handedness in plasmas
of relativistic particles can lead to exponential growth of a helical magnetic
field via a small-scale chiral dynamo instability known as the chiral magnetic
effect. Here, we show, using dimensional arguments and numerical simulations,
that this process produces through the Lorentz force chiral magnetically driven
turbulence. A k^{-2} magnetic energy spectrum emerges via inverse transfer over
a certain range of wavenumbers k. The total chirality (magnetic helicity plus
normalized chiral chemical potential) is conserved in this system. Therefore,
as the helical magnetic field grows, most of the total chirality gets
transferred into magnetic helicity until the chiral magnetic effect terminates.
Quantitative results for height, slope, and extent of the spectrum are
obtained. Consequences of this effect for cosmic magnetic fields are discussed.Comment: 7 pages, 4 figures, 1 table, published in ApJ
Universality in Quantum Hall Systems: Coset Construction of Incompressible States
Incompressible Quantum Hall fluids (QHF's) can be described in the scaling limit by three-dimensional topological field theories. Thanks to the correspondence between three-dimensional topological field theories and two dimensional chiral conformal field theories (CCFT's), we propose to study QHF's from the point of view of CCFT's. We derive consistency conditions and stability criteria for those CCFT's that can be expected to describe a QHF. A general algorithm is presented which uses simple currents to construct interesting examples of such CCFT's. It generalizes the description of QHF's in terms of Quantum Hall lattices. Explicit examples, based on the coset construction, provide candidates for the description of Quantum Hall fluids with Hall conductivity s_H=1/2 e^2/h, 1/4 e^2/h, 3/5 e^2/h, e^2/h,..
Brief exposure to directionally-specific pulsed electromagnetic fields stimulates extracellular vesicle release and is antagonized by streptomycin: A potential regenerative medicine and food industry paradigm
10.1016/j.biomaterials.2022.121658BIOMATERIALS28