1,241 research outputs found
EPFL Lectures on Conformal Field Theory in D>= 3 Dimensions
This is a writeup of lectures given at the EPFL Lausanne in the fall of 2012.
The topics covered: physical foundations of conformal symmetry, conformal
kinematics, radial quantization and the OPE, and a very basic introduction to
conformal bootstrap.Comment: 68 pages; v2 - misprints correcte
Radial Coordinates for Conformal Blocks
We develop the theory of conformal blocks in CFT_d expressing them as power
series with Gegenbauer polynomial coefficients. Such series have a clear
physical meaning when the conformal block is analyzed in radial quantization:
individual terms describe contributions of descendants of a given spin.
Convergence of these series can be optimized by a judicious choice of the
radial quantization origin. We argue that the best choice is to insert the
operators symmetrically. We analyze in detail the resulting "rho-series" and
show that it converges much more rapidly than for the commonly used variable z.
We discuss how these conformal block representations can be used in the
conformal bootstrap. In particular, we use them to derive analytically some
bootstrap bounds whose existence was previously found numerically.Comment: 27 pages, 9 figures; v2: misprints correcte
A tauberian theorem for the conformal bootstrap
For expansions in one-dimensional conformal blocks, we provide a rigorous
link between the asymptotics of the spectral density of exchanged primaries and
the leading singularity in the crossed channel. Our result has a direct
application to systems of SL(2,R)-invariant correlators (also known as 1d
CFTs). It also puts on solid ground a part of the lightcone bootstrap analysis
of the spectrum of operators of high spin and bounded twist in CFTs in d>2. In
addition, a similar argument controls the spectral density asymptotics in large
N gauge theories.Comment: 36pp; v2: refs and comments added, misprints correcte
Classical Black Hole Production In Quantum Particle Collisions
The semiclassical picture of black hole production in trans-Planckian
elementary particle collisions is reviewed.Comment: 5 pages, 7 figures; talk given at the 6th Alexander Friedmann
International Seminar on Gravitation and Cosmology, Cargese, France, June
28-July 3, 2004; to appear in the proceedings (Int.J.Mod.Phys.A); v2: typos
correcte
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