2,213 research outputs found
Ergodic solenoids and generalized currents
We introduce the concept of solenoid as an abstract laminated space. We do a
thorough study of solenoids, leading to the notion of ergodic and uniquely
ergodic solenoids. We define generalized currents associated with immersions of
oriented solenoids with a transversal measure into smooth manifolds,
generalizing Ruelle-Sullivan currents.Comment: 28 pages, 2 figures. Fully revised presentation of the paper.
Accepted in Revista Matematica Complutense. The final publication is
available at http://www.springerlink.co
Ergodic solenoidal homology: density of ergodic solenoids
A measured solenoid is a laminated space endowed with a tranversal measure
invariant by holonomy, as defined in arXiv:0910.2836. A measured solenoid
immersed in a smooth manifold produces a closed current (known as generalized
Ruelle-Sullivan current). Uniquely ergodic solenoids are those for which there
is a unique (up to scalars) transversal measure. By the results in
arXiv:0910.2913, for any smooth manifold, any real homology class is
represented by a uniquely ergodic solenoid. In this paper, we prove that the
currents associated to uniquely ergodic solenoids are dense in the space of
closed currents, therefore proving the abundance of such objects.Comment: 9 pages, 2 figure
Double parton correlations in Light-Front constituent quark model
Double parton distribution functions (dPDF) represent a tool to explore the
3D proton structure. They can be measured in high energy proton-proton and
proton nucleus collisions and encode information on how partons inside a proton
are correlated among each other. dPFDs are studied here in the valence quark
region, by means of a constituent quark model, where two particle correlations
are present without any additional prescription. This framework allows to
understand the dynamical origin of the correlations and to clarify which, among
the features of the results, are model independent. Use will be made of a
relativistic light-front scheme, able to overcome some drawbacks of the
previous calculation. Transverse momentum correlations, due to the exact
treatment of the boosts, are predicted and analyzed. The role of spin
correlations is also shown. Due to the covariance of the approach, some
symmetries of the dPDFs are seen unambigously. For the valence sector, the
study of the QCD evolution of the model results, which can be performed safely
thanks to the property of good support, has been also completed.Comment: 8 pages, 12 figures, invited talk at the "XLIV ISMD Conference",
Bologna, Italy, 8-12 September 2014. Submitted to EPJ Web of Conference
A model calculation of double parton distribution functions of the pion
Two-parton correlations in the pion are investigated in terms of double
parton distribution functions. A Poincar\'e covariant Light-Front framework has
been adopted. As non perturbative input, the pion wave function obtained within
the so-called soft-wall AdS/QCD model has been used. Results show how novel
dynamical information on the structure of the pion, not accessible through
one-body parton distribution, are encoded in double parton distribution
functions.Comment: 14 pages, 8 figure
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