1,827 research outputs found
Comment on triple gauge boson interactions in the non-commutative electroweak sector
In this comment we present an analysis of electroweak neutral triple gauge
boson couplings projected out of the gauge sector of the extended
non-commutative standard model. A brief overview of the current experimental
situation is given.Comment: 4 page
The Standard Model on Non-Commutative Space-Time
We consider the Standard Model on a non-commutative space and expand the
action in the non-commutativity parameter theta. No new particles are
introduced, the structure group is SU(3) x SU(2) x U(1). We derive the leading
order action. At zeroth order the action coincides with the ordinary Standard
Model. At leading order in theta we find new vertices which are absent in the
Standard Model on commutative space-time. The most striking features are
couplings between quarks, gluons and electroweak bosons and many new vertices
in the charged and neutral currents. We find that parity is violated in
non-commutative QCD. The Higgs mechanism can be applied. QED is not deformed in
the minimal version of the NCSM to the order considered.Comment: 28 pages, v3: typos corrected, new appendix on alternative kinetic
terms for gauge bosons; v4: typos correcte
An algebraic formulation of nonassociative quantum mechanics
We develop a suitably general version of quantum mechanics that can handle
nonassociative algebras of observables and which reduces to standard quantum
theory in the traditional associative setting. Our algebraic approach is
naturally probabilistic and is based on the universal enveloping algebra of a
general nonassociative algebra. We formulate properties of states together with
notions of trace, and use them to develop GNS constructions. We describe
Heisenberg and Schrodinger pictures of completely positive dynamics, and we
illustrate our formalism on the explicit examples of finite-dimensional matrix
Jordan algebras as well as the octonion algebra.Comment: 34 pages; v2: minor correction
Non-Geometric Fluxes, Quasi-Hopf Twist Deformations and Nonassociative Quantum Mechanics
We analyse the symmetries underlying nonassociative deformations of geometry
in non-geometric R-flux compactifications which arise via T-duality from closed
strings with constant geometric fluxes. Starting from the non-abelian Lie
algebra of translations and Bopp shifts in phase space, together with a
suitable cochain twist, we construct the quasi-Hopf algebra of symmetries that
deforms the algebra of functions and the exterior differential calculus in the
phase space description of nonassociative R-space. In this setting
nonassociativity is characterised by the associator 3-cocycle which controls
non-coassociativity of the quasi-Hopf algebra. We use abelian 2-cocycle twists
to construct maps between the dynamical nonassociative star product and a
family of associative star products parametrized by constant momentum surfaces
in phase space. We define a suitable integration on these nonassociative spaces
and find that the usual cyclicity of associative noncommutative deformations is
replaced by weaker notions of 2-cyclicity and 3-cyclicity. Using this star
product quantization on phase space together with 3-cyclicity, we formulate a
consistent version of nonassociative quantum mechanics, in which we calculate
the expectation values of area and volume operators, and find coarse-graining
of the string background due to the R-flux.Comment: 38 pages; v2: typos corrected, reference added; v3: typos corrected,
comments about cyclicity added in section 4.2, references updated; Final
version to be published in Journal of Mathematical Physic
Long-Term Antecedents and Outcomes of Perceived Control
Perceived control plays an important role in shaping development throughout adulthood and old age. Using data from the adult lifespan sample of the national German Socio-Economic Panel (SOEP; N > 10,000, covering 25 years of measurement), we explored long-term antecedents, correlates, and outcomes of perceived control and examined if associations differ with age. Targeting correlates and antecedents of control, findings indicated that higher concurrent levels of social participation, life satisfaction, and self-rated health as well as more positive changes in social participation over the preceding 11 years were each predictive of between-person differences in perceived control. Targeting health outcomes of control, survival analyses revealed that perceived control predicted 14-year hazard rates for disability (n = 996 became disabled) and mortality (n = 1,382 died). The effect for mortality, but not for disability, was independent of socio-demographic and psychosocial factors. Overall, we found very limited support for age-differential associations. Our results provide further impetus to thoroughly examine processes involved in antecedent-consequent relations among perceived control, facets of social life, well-being, and health.Control, lifespan development, disability, mortality, psychosocial
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