40 research outputs found
String Theory and Turbulence
We propose a string theory of turbulence that explains the Kolmogorov scaling
in 3+1 dimensions and the Kraichnan and Kolmogorov scalings in 2+1 dimensions.
This string theory of turbulence should be understood in light of the AdS/CFT
dictionary. Our argument is crucially based on the use of Migdal's loop
variables and the self-consistent solutions of Migdal's loop equations for
turbulence. In particular, there is an area law for turbulence in 2+1
dimensions related to the Kraichnan scaling.Comment: LaTeX; 15 pages, two figures; v.2: slight changes to text, footnotes
and references adde
Quantum Gravity and Turbulence
We apply recent advances in quantum gravity to the problem of turbulence.
Adopting the AdS/CFT approach we propose a string theory of turbulence that
explains the Kolmogorov scaling in 3+1 dimensions and the Kraichnan and
Kolmogorov scalings in 2+1 dimensions. In the gravitational context, turbulence
is intimately related to the properties of spacetime, or quantum, foam.Comment: 8 pages, LaTeX; Honorable Mention in the 2010 Gravity Research
Foundation Essay Contes
Bell's Inequalities, Superquantum Correlations, and String Theory
We offer an interpretation of super-quantum correlations in terms of a
"doubly" quantum theory. We argue that string theory, viewed as a quantum
theory with two deformation parameters, the string tension \alpha' and the
string coupling constant g_s, is such a super-quantum theory, one that
transgresses the usual quantum violations of Bell's inequalities. We also
discuss the \hbar\to\infty limit of quantum mechanics in this context. As a
super-quantum theory, string theory should display distinct experimentally
observable super-correlations of entangled stringy states.Comment: 7 pages, revtex
Toward a Background Independent Quantum Theory of Gravity
Any canonical quantum theory can be understood to arise from the
compatibility of the statistical geometry of distinguishable observations with
the canonical Poisson structure of Hamiltonian dynamics. This geometric
perspective offers a novel, background independent non-perturbative formulation
of quantum gravity. We invoke a quantum version of the equivalence principle,
which requires both the statistical and symplectic geometries of canonical
quantum theory to be fully dynamical quantities. Our approach sheds new light
on such basic issues of quantum gravity as the nature of observables, the
problem of time, and the physics of the vacuum. In particular, the observed
numerical smallness of the cosmological constant can be rationalized in this
approach.Comment: Awarded Honorable Mention, 2004 Gravity Research Foundation Essay
Competition; 8 pages, LaTe
Inconsistency of QED in the Presence of Dirac Monopoles
A precise formulation of local gauge invariance in QED is presented,
which clearly shows that the gauge coupling associated with the unphysical
longitudinal photon field is non-observable and actually has an arbitrary
value. We then re-examine the Dirac quantization condition and find that its
derivation involves solely the unphysical longitudinal coupling. Hence an
inconsistency inevitably arises in the presence of Dirac monopoles and this can
be considered as a theoretical evidence against their existence. An
alternative, independent proof of this conclusion is also presented.Comment: Extended and combined version, refinements added; 20 LaTex pages,
Published in Z. Phys. C65, pp.175-18
Modeling Time's Arrow
Quantum gravity, the initial low entropy state of the Universe, and the
problem of time are interlocking puzzles. In this article, we address the
origin of the arrow of time from a cosmological perspective motivated by a
novel approach to quantum gravitation. Our proposal is based on a quantum
counterpart of the equivalence principle, a general covariance of the dynamical
phase space. We discuss how the nonlinear dynamics of such a system provides a
natural description for cosmological evolution in the early Universe. We also
underscore connections between the proposed non-perturbative quantum gravity
model and fundamental questions in non-equilibrium statistical physics.Comment: 18 page
Lifetime Risks, Projected Numbers, and Adverse Outcomes in Asian Patients With Atrial Fibrillation::A Report From the Taiwan Nationwide AF Cohort Study
The Big Bang as the Ultimate Traffic Jam
We present a novel solution to the nature and formation of the initial state
of the Universe. It derives from the physics of a generally covariant extension
of Matrix theory. We focus on the dynamical state space of this background
independent quantum theory of gravity and matter, an infinite dimensional,
complex non-linear Grassmannian. When this space is endowed with a
Fubini--Study-like metric, the associated geodesic distance between any two of
its points is zero. This striking mathematical result translates into a
physical description of a hot, zero entropy Big Bang. The latter is then seen
as a far from equilibrium, large fluctuation driven, metastable ordered
transition, a ``freezing by heating'' jamming transition. Moreover, the
subsequent unjamming transition could provide a mechanism for inflation while
rejamming may model a Big Crunch, the final state of gravitational collapse.Comment: 8 pages, This essay received an honorable mention in the Gravity
Research Foundation Essay Competition, 200