6 research outputs found
Energy Landscape of d-Dimensional Q-balls
We investigate the properties of -balls in spatial dimensions. First,
a generalized virial relation for these objects is obtained. We then focus on
potentials ,
where is a constant and is an integer, obtaining variational
estimates for their energies for arbitrary charge . These analytical
estimates are contrasted with numerical results and their accuracy evaluated.
Based on the results, we offer a simple criterion to classify ``large'' and
``small'' -dimensional -balls for this class of potentials. A minimum
charge is then computed and its dependence on spatial dimensionality is shown
to scale as . We also briefly investigate the
existence of -clouds in dimensions.Comment: 13 pages, 10 figures, final version to appear in Physical Review D.
Small correction
Prebiotic Homochirality as a Critical Phenomenon
The development of prebiotic homochirality on early-Earth or another
planetary platform may be viewed as a critical phenomenon. It is shown, in the
context of spatio-temporal polymerization reaction networks, that environmental
effects -- be them temperature surges or other external disruptions -- may
destroy any net chirality previously produced. In order to understand the
emergence of prebiotic homochirality it is important to model the coupling of
polymerization reaction networks to different planetary environments.Comment: 6 Pages, 1 Figure, In Press: Origins of Life and Evolution of
Biosphere
Punctuated Chirality
Most biomolecules occur in mirror, or chiral, images of each other. However,
life is homochiral: proteins contain almost exclusively levorotatory (L) amino
acids, while only dextrorotatory (R) sugars appear in RNA and DNA. The
mechanism behind this fundamental asymmetry of life remains an open problem.
Coupling the spatiotemporal evolution of a general autocatalytic polymerization
reaction network to external environmental effects, we show through a detailed
statistical analysis that high intensity and long duration events may drive
achiral initial conditions towards chirality. We argue that life's
homochirality resulted from sequential chiral symmetry breaking triggered by
environmental events, thus extending the theory of punctuated equilibrium to
the prebiotic realm. Applying our arguments to other potentially life-bearing
planetary platforms, we predict that a statistically representative sampling
will be racemic on average.Comment: 13 pages, 4 color figures. Final version published in Origins of Life
and Evolution of Biospheres. Typos corrected, figures improved, and a few
definitions and word usage clarifie