9,712 research outputs found
A p-adic Perron-Frobenius Theorem
We prove that if an matrix defined over (or more
generally an arbitrary complete, discretely-valued, non-Archimedean field)
satisfies a certain congruence property, then it has a strictly maximal
eigenvalue in , and that iteration of the (normalized) matrix
converges to a projection operator onto the corresponding eigenspace. This
result may be viewed as a -adic analogue of the Perron-Frobenius theorem for
positive real matrices
Unity of pomerons from gauge/string duality
We develop a formalism where the hard and soft pomeron contributions to high
energy scattering arise as leading Regge poles of a single kernel in
holographic QCD. The kernel is obtained using effective field theory inspired
by Regge theory of a 5-d string theory. It describes the exchange of higher
spin fields in the graviton Regge trajectory that are dual to glueball states
of twist two. For a specific holographic QCD model we describe Deep Inelastic
Scattering in the Regge limit of low Bjorken x, finding good agreement with
experimental data from HERA. The observed rise of the effective pomeron
intercept, as the size of the probe decreases, is reproduced by considering the
first four pomeron trajectories. In the case of soft probes, relevant to total
cross sections, the leading hard pomeron trajectory is suppressed, such that in
this kinematical region we reproduce an intercept of 1.09 compatible with the
QCD soft pomeron data. In the spectral region of positive Maldelstam variable t
the first two pomeron trajectories are consistent with current expectations for
the glueball spectrum from lattice simulations
Duino-Based Learning (DBL) in control engineering courses
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThis document presents a project to develop freely redistributable materials to conduct educational lab projects with MATLAB, Simulink, Arduino and low-cost plants. This work materials introduce the fundamentals of Control Engineering through exercises and videos. Along with all this, the most important steps and issues appeared in the project are explained, so anyone interested on doing a project can have a starting point instead of starting a project from scratch, which most of times this results hard to implementPeer ReviewedPostprint (author's final draft
Soft Pomeron in Holographic QCD
We study the graviton Regge trajectory in Holographic QCD as a model for high
energy scattering processes dominated by soft pomeron exchange. This is done by
considering spin J fields from the closed string sector that are dual to
glueball states of even spin and parity. In particular, we construct a model
that governs the analytic continuation of the spin J field equation to the
region of real J < 2, which includes the scattering domain of negative
Maldelstam variable t. The model leads to approximately linear Regge
trajectories and is compatible with the measured values of 1.08 for the
intercept and 0.25 GeV for the slope of the soft pomeron. The intercept
of the secondary pomeron trajectory is in the same region of the subleading
trajectories, made of mesons, proposed by Donnachie and Landshoff, and should
therefore be taken into account.Comment: 7 pages, 5 figures. V2 : The paper has been expanded to provide more
details of the model and results. Added two new figures and two new
references; corrected typo
The emergence of sex differences in personality traits in early adolescence: a cross-sectional, cross-cultural study
Although large international studies have found consistent patterns of sex differences in personality traits among adults (i.e., women scoring higher on most facets), less is known about cross-cultural sex differences in adolescent personality and the role of culture and age in shaping them. The present study examines the NEO Personality Inventory-3 (McCrae, Costa, & Martin, 2005) informant ratings of adolescents from 23 cultures (N = 4,850), and investigates culture and age as sources of variability in sex differences of adolescents' personality. The effect for Neuroticism (with females scoring higher than males) begins to take on its adult form around age 14. Girls score higher on Openness to Experience and Conscientiousness at all ages between 12 and 17 years. A more complex pattern emerges for Extraversion and Agreeableness, although by age 17, sex differences for these traits are highly similar to those observed in adulthood. Cross-sectional data suggest that (a) with advancing age, sex differences found in adolescents increasingly converge toward adult patterns with respect to both direction and magnitude; (b) girls display sex-typed personality traits at an earlier age than boys; and (c) the emergence of sex differences was similar across cultures. Practical implications of the present findings are discussed
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