Neutrinos from active black holes, sources of ultra high energy cosmic rays

A correlation between the highest energy Cosmic Rays (above ~ EeV) and the distribution of active galactic nuclei (AGN) gives rise to a prediction of neutrino production in the same sources. In this paper, we present a detailed AGN model, predicting neutrino production near the foot of the jet, where the photon fields from the disk and synchrotron radiation from the jet itself create high optical depths for proton-photon interactions. The protons escape from later shocks where the emission region is optically thin for proton-photon interactions. Consequently, Cosmic Rays are predicted to come from FR-I galaxies, independent of the orientation of the source. Neutrinos, on the other hand, are only observable from sources directing their jet towards Earth, i.e. flat spectrum radio sources and in particular BL Lac type objects, due to the strongly boosted neutrino emission.Comment: Accepted for publication in Astroparticle Physics; 30 pages, 8 figure

E11E_{11}, Borcherds algebras and maximal supergravity

The dynamical $p$-forms of torus reductions of maximal supergravity theory have been shown some time ago to possess remarkable algebraic structures. The set ("dynamical spectrum") of propagating $p$-forms has been described as a (truncation of a) real Borcherds superalgebra \mf{V}_D that is characterized concisely by a Cartan matrix which has been constructed explicitly for each spacetime dimension $11 \geq D \geq 3.$ In the equations of motion, each differential form of degree $p$ is the coefficient of a (super-) group generator, which is itself of degree $p$ for a specific gradation (the \mf{V}-gradation). A slightly milder truncation of the Borcherds superalgebra enables one to predict also the "spectrum" of the non-dynamical $(D - 1)$ and $D$-forms. The maximal supergravity $p$-form spectra were reanalyzed more recently by truncation of the field spectrum of $E_{11}$ to the $p$-forms that are relevant after reduction from 11 to $D$ dimensions. We show in this paper how the Borcherds description can be systematically derived from the split ("maximally non compact") real form of $E_{11}$ for $D \geq 1.$ This explains not only why both structures lead to the same propagating $p$-forms and their duals for $p\leq (D - 2),$ but also why one obtains the same $(D - 1)$-forms and "top" $D$-forms. The Borcherds symmetries \mf{V}_2 and \mf{V}_1 are new too. We also introduce and use the concept of a presentation of a Lie algebra that is covariant under a given subalgebra.Comment: 39 pages. Version 2 contains improved presentation in particular an extra appendix B giving details on the infinite rank limit possibility. Version to appear in JHE

A bidirectional relationship between physical activity and executive function in older adults

Michael Daly gratefully acknowledges funding support from the Economic and Social Research Council (ES/L010437/1). David McMinn was funded by the Scottish Government, Rural and Environment Science & Analytical Services (RESAS) division. The funders had no role in study design, data collection and analysis, interpolation of these data, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

A bidirectional relationship between executive function and health behavior : evidence, implications, and future directions

This work was supported by a grant from the UK Economic and Social Research Council (ES/L010437/1).Peer reviewedPublisher PD