2,365 research outputs found
Bounded holomorphic functions attaining their norms in the bidual
Under certain hypotheses on the Banach space , we prove that the set of
analytic functions in (the algebra of all holomorphic and
uniformly continuous functions in the ball of ) whose Aron-Berner extensions
attain their norms, is dense in . The result holds also for
functions with values in a dual space or in a Banach space with the so-called
property . For this, we establish first a Lindenstrauss type theorem
for continuous polynomials. We also present some counterexamples for the
Bishop-Phelps theorem in the analytic and polynomial cases where our results
apply.Comment: Accepted in Publ. Res. Inst. Math. Sc
Higgs Boson Pair Production at Next-to-Next-to-Leading Order in QCD
We compute the next-to-next-to-leading order QCD corrections for Standard
Model Higgs boson pair production inclusive cross section at hadron colliders
within the large top-mass approximation. We provide numerical results for the
LHC, finding that the corrections are large, resulting in an increase of with respect to the next-to-leading order result at c.m. energy
. We observe a substantial reduction in the scale
dependence, with overlap between the current and previous order prediction. All
our results are normalized using the full top- and bottom-mass dependence at
leading order. We also provide analytical expressions for the K factors as a
function of
Ultraviolet cutoffs for quantum fields in cosmological spacetimes
We analyze critically the renormalization of quantum fields in cosmological
spacetimes, using non covariant ultraviolet cutoffs. We compute explicitly the
counterterms necessary to renormalize the semiclassical Einstein equations,
using comoving and physical ultraviolet cutoffs. In the first case, the
divergences renormalize bare conserved fluids, while in the second case it is
necessary to break the covariance of the bare theory. We point out that, in
general, the renormalized equations differ from those obtained with covariant
methods, even after absorbing the infinities and choosing the renormalized
parameters to force the consistency of the renormalized theory. We repeat the
analysis for the evolution equation for the mean value of an interacting scalar
fieldComment: 19 pages. Minor changes. References adde
Two-loop virtual corrections to Higgs pair production
We present the two-loop virtual corrections to Standard Model Higgs boson
pair production via gluon fusion in the heavy top quark limit. Based
on this result, we evaluate the corresponding cross section at the LHC at 14
TeV in the next-to-next-to-leading order soft-virtual approximation. We find an
inclusive K-factor of about 2.4, resulting in an increase close to 23% with
respect to the previous available calculation at next-to-leading order. As
expected, we observe a considerable reduction in the renormalization and
factorization scale dependence
Next-to-Next-to-Leading Order QCD Corrections to Higgs Boson Pair Production
We present the Higgs boson pair production cross section at
next-to-next-to-leading order in QCD within the large top-mass approximation.
Numerical results for the LHC are provided, finding an increase of O(20%) with
respect to the previous order prediction and a substantial reduction in the
scale dependence. We normalize our results using the full top- and bottom-mass
dependence at leading order.Comment: Proceedings of 'Loops & Legs 2014', Weimar (Germany), April/May 201
Two-loop corrections to the triple Higgs boson production cross section
In this paper we compute the QCD corrections for the triple Higgs boson
production cross section via gluon fusion, within the heavy-top approximation.
We present, for the first time, analytical results for the next-to-leading
order corrections, and also compute the soft and virtual contributions of the
next-to-next-to-leading order cross section. We provide predictions for the
total cross section and the triple Higgs invariant mass distribution. We find
that the QCD corrections are large at both perturbative orders, and that the
scale uncertainty is substantially reduced when the second order perturbative
corrections are included.Comment: 12 pages, 4 figures. v2: added analysis for non-SM self-couplings,
and other minor corrections. To be published in JHE
A Lindenstrauss theorem for some classes of multilinear mappings
Under some natural hypotheses, we show that if a multilinear mapping belongs
to some Banach multlinear ideal, then it can be approximated by multilinear
mappings belonging to the same ideal whose Arens extensions simultaneously
attain their norms. We also consider the class of symmetric multilinear
mappings.Comment: 11 page
Domain wall interactions due to vacuum Dirac field fluctuations in 2+1 dimensions
We evaluate quantum effects due to a -component Dirac field in
space-time dimensions, coupled to domain-wall like defects with a smooth shape.
We show that those effects induce non trivial contributions to the
(shape-dependent) energy of the domain walls. For a single defect, we study the
divergences in the corresponding self-energy, and also consider the role of the
massless zero mode, corresponding to the Callan-Harvey mechanism, by coupling
the Dirac field to an external gauge field. For two defects, we show that the
Dirac field induces a non trivial, Casimir-like effect between them, and
provide an exact expression for that interaction in the case of two
straight-line parallel defects. As is the case for the Casimir interaction
energy, the result is finite and unambiguous.Comment: 17 pages, 1 figur
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