9,053 research outputs found
Interpolation categories for homology theories
For a homological functor from a triangulated category to an abelian category
satisfying some technical assumptions we construct a tower of interpolation
categories. These are categories over which the functor factorizes and which
capture more and more information according to the injective dimension of the
images of the functor. The categories are obtained by proving the existence of
truncated versions of resolution or -model structures. Examples of
functors fitting in our framework are given by every generalized homology
theory represented by a ring spectrum satisfying the Adams-Atiyah condition.
The constructions are closely related to the modified Adams spectral sequence
and give a very conceptual approach to the associated moduli problem and
obstruction theory. As application we establish an isomorphism between certain
E(n)-local Picard groups and some Ext-groups.Comment: 40 pages, corrected version of second part of the replaced version,
first part will appear sepparately as "Truncated resolution model
structures", to appear in JPA
Full NLO electroweak corrections to Z-boson pair production at the Large Hadron Collider
We report on a recent calculation of the full next-to-leading-order
electroweak corrections to Z-boson pair production with subsequent decays into
four charged leptons. Using the complete matrix elements at leading order and
next-to-leading order in the electroweak coupling for the processes
and , this includes all
off-shell effects of intermediate massive vector bosons and photons. We employ
a gauge-invariant splitting for the electroweak corrections into purely weak
and photonic corrections. The latter show the well-known radiative tails near
kinematical thresholds or resonances. The former are generically at the level
of for the fiducial cross section and reach several in the
high-energy tails of distributions due to logarithms of electroweak origin. The
impact of interference effects due to equal-flavour leptons in the final state
can reach the order of in off-shell-sensitive regions. Photon-induced
contributions are included in our calculation, but turn out to be
phenomenologically unimportant.Comment: Proceedings to the XXV International Workshop on Deep-Inelastic
Scattering and Related Subjects, 3-7 April 2017, Birmingham, U
Calculus of functors and model categories II
This is a continuation, completion, and generalization of our previous joint
work with B. Chorny. We supply model structures and Quillen equivalences
underlying Goodwillie's constructions on the homotopy level for functors
between simplicial model categories satisfying mild hypotheses.Comment: 47 pages. Version 3 contains a new introduction and further small
changes, based on suggestions of the referee. To appear in "Algebraic and
Geometric Topology
Optimal designs for multivariable spline models
In this paper, we investigate optimal designs for multivariate additive spline regressionmodels. We assume that the knot locations are unknown, so must be estimated from thedata. In this situation, the Fisher information for the full parameter vector depends on theunknown knot locations, resulting in a non-linear design problem. We show that locally,Bayesian and maximin D-optimal designs can be found as the products of the optimaldesigns in one dimension. A similar result is proven for Q-optimality in the class of allproduct design
Electroweak corrections to vector-boson scattering
We report on a recent calculation of the complete NLO QCD and electroweak
corrections to the process , i.e. like-sign
charged vector-boson scattering. The computation is based on the complete
amplitudes involving two different orders of the strong and electroweak
coupling constants at tree level and three different orders at one-loop level.
We find electroweak corrections of for the fiducial cross section that
are an intrinsic feature of the vector-boson scattering process. For
differential distributions, the corrections reach up to in the
phase-space regions explored. At the NLO level a unique separation between
vector-boson scattering and irreducible background processes is not possible
any more at the level of Feynman diagrams.Comment: 6 pages, 8 eps figures, Prodeedings of the 13th International
Symposium on Radiative Corrections (Applications of Quantum Field Theory to
Phenomenology), 25-29 September, 2017, St. Gilgen, Austri
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