1,782,006 research outputs found
Power-law running of the effective gluon mass
The dynamically generated effective gluon mass is known to depend
non-trivially on the momentum, decreasing sufficiently fast in the deep
ultraviolet, in order for the renormalizability of QCD to be preserved. General
arguments based on the analogy with the constituent quark masses, as well as
explicit calculations using the operator-product expansion, suggest that the
gluon mass falls off as the inverse square of the momentum, relating it to the
gauge-invariant gluon condensate of dimension four. In this article we
demonstrate that the power-law running of the effective gluon mass is indeed
dynamically realized at the level of the non-perturbative Schwinger-Dyson
equation. We study a gauge-invariant non-linear integral equation involving the
gluon self-energy, and establish the conditions necessary for the existence of
infrared finite solutions, described in terms of a momentum-dependent gluon
mass. Assuming a simplified form for the gluon propagator, we derive a
secondary integral equation that controls the running of the mass in the deep
ultraviolet. Depending on the values chosen for certain parameters entering
into the Ansatz for the fully-dressed three-gluon vertex, this latter equation
yields either logarithmic solutions, familiar from previous linear studies, or
a new type of solutions, displaying power-law running. In addition, it
furnishes a non-trivial integral constraint, which restricts significantly (but
does not determine fully) the running of the mass in the intermediate and
infrared regimes. The numerical analysis presented is in complete agreement
with the analytic results obtained, showing clearly the appearance of the two
types of momentum-dependence, well-separated in the relevant space of
parameters. Open issues and future directions are briefly discussed.Comment: 37 pages, 5 figure
Outlines of presentations
Illinois Custom Spray Operators' School Outline of Presentations. January 12-14, 1949. This was the very first Spray Operator's School conference
Real hypersurfaces in complex two-plane Grassmannians with commuting restricted Jacobi operators
In this paper, we have considered a new commuting condition, that is,
\big(resp. (\Bar{R}_N\phi) S = S
(\Bar{R}_N\phi)\big) between the restricted Jacobi operator~ (resp.
\Bar{R}_N\phi), and the Ricci tensor for real hypersurfaces in
. In terms of this condition we give a complete
classification for Hopf hypersurfaces in
Localized Frames and Compactness
We introduce the concept of weak-localization for generalized frames and use
this concept to define a class of weakly localized operators. This class
contains many important operators, including: Short Time Fourier Transform
multipliers, Calderon-Toeplitz operators, Toeplitz operators on various
functions spaces, Anti-Wick operators, and many others. In this paper, we study
the boundedness and compactness of weakly localized operators. In particular,
we provide a characterization of compactness for weakly localized operators in
terms of the behavior of their Berezin transform
Logarithmic intertwining operators and vertex operators
This is the first in a series of papers where we study logarithmic
intertwining operators for various vertex subalgebras of Heisenberg vertex
operator algebras. In this paper we examine logarithmic intertwining operators
associated with rank one Heisenberg vertex operator algebra , of
central charge . We classify these operators in terms of {\em depth}
and provide explicit constructions in all cases. Furthermore, for we
focus on the vertex operator subalgebra L(1,0) of and obtain
logarithmic intertwining operators among indecomposable Virasoro algebra
modules. In particular, we construct explicitly a family of {\em hidden}
logarithmic intertwining operators, i.e., those that operate among two ordinary
and one genuine logarithmic L(1,0)-module.Comment: 32 pages. To appear in CM
On nonlocal quasilinear equations and their local limits
We introduce a new class of quasilinear nonlocal operators and study
equations involving these operators. The operators are degenerate elliptic and
may have arbitrary growth in the gradient. Included are new nonlocal versions
of p-Laplace, -Laplace, mean curvature of graph, and even strongly
degenerate operators, in addition to some nonlocal quasilinear operators
appearing in the existing literature. Our main results are comparison,
uniqueness, and existence results for viscosity solutions of linear and fully
nonlinear equations involving these operators. Because of the structure of our
operators, especially the existence proof is highly non-trivial and
non-standard. We also identify the conditions under which the nonlocal
operators converge to local quasilinear operators, and show that the solutions
of the corresponding nonlocal equations converge to the solutions of the local
limit equations. Finally, we give a (formal) stochastic representation formula
for the solutions and provide many examples
Renormalization Group Running of Dimension-Six Sources of Parity and Time-Reversal Violation
We perform a systematic study of flavor-diagonal parity- and
time-reversal-violating operators of dimension six which could arise from
physics beyond the SM. We begin at the unknown high-energy scale where these
operators originate. At this scale the operators are constrained by gauge
invariance which has important consequences for the form of effective operators
at lower energies. In particular for the four-quark operators. We calculate
one-loop QCD and, when necessary, electroweak corrections to the operators and
evolve them down to the electroweak scale and subsequently to hadronic scales.
We find that for most operators QCD corrections are not particularly
significant. We derive a set of operators at low energy which is expected to
dominate hadronic and nuclear EDMs due to physics beyond the SM and obtain
quantitative relations between these operators and the original dimension-six
operators at the high-energy scale. We use the limit on the neutron EDM to set
bounds on the dimension-six operators.Comment: Matches published version, 35 pages, 6 figures, minor correction
- …
