6,567 research outputs found
Multitoroidal configurations as equilibrium flow eigenstates
Equilibrium eigenstates of an axisymmetric magnetically confined plasma with
toroidal flow are investigated by means of exact solutions of the ideal
magnetohydrodynamic equations. The study includes "compressible" flows with
constant temperature, but varying density on magnetic surfaces and
incompressible ones with constant density, but varying temperature thereon. In
both cases eigenfunctions of the form Psi_{nl} = Z_l(z)R_n(R) (l, n=1,2,...)
describe configurations with lxn magnetic axes. By varying the flow parameters
a change in magnetic topology is possible. In addition, the effects of the flow
and the aspect ratio on the Shafranov shift are evaluated along with the
variations of density and temperature on magnetic surfaces.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
The Schwarzian Theory - A Wilson Line Perspective
We provide a holographic perspective on correlation functions in Schwarzian
quantum mechanics, as boundary-anchored Wilson line correlators in
Jackiw-Teitelboim gravity. We first study compact groups and identify the
diagrammatic representation of bilocal correlators of the particle-on-a-group
model as Wilson line correlators in its 2d holographic BF description. We
generalize to the Hamiltonian reduction of SL(2,R) and derive the Schwarzian
correlation functions. Out-of-time ordered correlators are determined by
crossing Wilson lines, giving a 6j-symbol, in agreement with 2d CFT results.Comment: 28 pages + appendices, v3: corrected discussion on representation
theory and improved discussion on higher-point functions in appendices,
references added, typos corrected, matches published versio
Clocks and Rods in Jackiw-Teitelboim Quantum Gravity
We specify bulk coordinates in Jackiw-Teitelboim (JT) gravity using a
boundary-intrinsic radar definition. This allows us to study and calculate
exactly diff-invariant bulk correlation functions of matter-coupled JT gravity,
which are found to satisfy microcausality. We observe that quantum gravity
effects dominate near-horizon matter correlation functions. This shows that
quantum matter in classical curved spacetime is not a sensible model for
near-horizon matter-coupled JT gravity. This is how JT gravity, given our
choice of bulk frame, evades an information paradox. This echoes into the
quantum expectation value of the near-horizon metric, whose analysis is
extended from the disk model to the recently proposed topological completion of
JT gravity. Due to quantum effects, at distances of order the Planck length to
the horizon, a dramatic breakdown of Rindler geometry is observed.Comment: 37 pages + appendices, v4: improved discussion on conformal anomaly
and choice of bulk observable, added appendix on massive bulk correlators and
global conformal blocks, corrected several equations in section 5 and
appendix E, typos corrected, matches published versio
Unruh detectors and quantum chaos in JT gravity
We identify the spectral properties of Hawking-Unruh radiation in the eternal
black hole at ultra low energies as a probe for the chaotic level statistics of
quantum black holes. Level repulsion implies that there are barely Hawking
particles with an energy smaller than the level separation. This effect is
experimentally accessible by probing the Unruh heat bath with a linear
detector. We provide evidence for this effect via explicit and exact
calculations in JT gravity building on a radar definition of bulk observables
in the model. Similar results are observed for the bath energy density. This
universal feature of eternal Hawking radiation should resonate into the
evaporating setup.Comment: 41 pages, v2: added references, fixed some typo
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