12,626 research outputs found
Field-control, phase-transitions, and life's emergence
Instances of critical-like characteristics in living systems at each
organizational level as well as the spontaneous emergence of computation
(Langton), indicate the relevance of self-organized criticality (SOC). But
extrapolating complex bio-systems to life's origins, brings up a paradox: how
could simple organics--lacking the 'soft matter' response properties of today's
bio-molecules--have dissipated energy from primordial reactions in a controlled
manner for their 'ordering'? Nevertheless, a causal link of life's macroscopic
irreversible dynamics to the microscopic reversible laws of statistical
mechanics is indicated via the 'functional-takeover' of a soft magnetic
scaffold by organics (c.f. Cairns-Smith's 'crystal-scaffold'). A
field-controlled structure offers a mechanism for bootstrapping--bottom-up
assembly with top-down control: its super-paramagnetic components obey
reversible dynamics, but its dissipation of H-field energy for aggregation
breaks time-reversal symmetry. The responsive adjustments of the controlled
(host) mineral system to environmental changes would bring about mutual
coupling between random organic sets supported by it; here the generation of
long-range correlations within organic (guest) networks could include SOC-like
mechanisms. And, such cooperative adjustments enable the selection of the
functional configuration by altering the inorganic network's capacity to assist
a spontaneous process. A non-equilibrium dynamics could now drive the
kinetically-oriented system towards a series of phase-transitions with
appropriate organic replacements 'taking-over' its functions.Comment: 54 pages, pdf fil
Interlinked 3D and 4D 3-Quark Wave Functions in a Bethe-Salpeter Model
Using the method of Green's functions within the framework of a
Bethe-Salpeter formalism characterized by a pairwise interaction with a 3D
support to its kernel (expressed in a Lorentz-covariant manner), the 4D BS wave
function for a system of three identical relativistic spinless quarks is
reconstructed from the corresponding 3D form which satisfies a {\it fully
connected} 3D BSE. This result is a 3-body generalization of a similar
interconnection between the 3D and 4D 2-body wave functions that had been found
earlier under identical conditions of a 3D support to the corresponding BS
kernel, using the ansatz of Covariant Instaneity for the pairwise
interaction. The generalization from spinless to fermion quarks is
straightforward.Comment: 13 pages, Latex. e.mail: [email protected]
Can Environmental Decoherence be Reversed for an Open Quantum System in a Magnetic field ?
A simple model is considered for an open system consisting of an aggregation
of magnetic particles (like greigite) in the presence of a magnetic field (H),
and interacting linearly with a bath of 3D harmonic oscillators. Using the
Feynman-Vernon formalism, as given in Weiss (termed FVW), the time-evolved
reduced density matrix (after eliminating the bath d.o.f.'s), is examined for
environmental decoherence as defined in the FVW formalism. While decoherence is
usually positive for most two-way couplings with the enviroment, it is found
that a interaction involving the system plus bath plus H-field all
together, can facilitate a of sign of this quantity! This may have
implications for quantum coherence based phenomena on the origins of life.Comment: 8 pages on pd
Minimum Of QCD Effective Action As Test Of QCD Confinement Parameter
A new approach to the non-perturbative regime of QCD is proposed by
introducing a (non-hermitian) field related to the usual gluon field by
= where goes to zero after
differentiation, and is a parameter which `runs' with momentum ().
An exact treatment yields a structure for the gluon
propagator, where =, showing
confinement in the instantaneous limit. This propagator was recently employed
to evaluate some basic condensates and their temperature dependence (in the
cosmological context), which were all reproduced for (termed the
`confinement scale parameter'), in association with the QCD scale parameter
[hep-ph/0109278]. This paper seeks to provide a formal
basis for the ratio by employing the minimality condition
for the effective action , up to the 2-loop level, using
the Cornwall-Jackiw formalism for composite operators. To that end the mass
function , determined via the Schwinger-Dyson equation (as a zero of the
functional derivative of w.r.t ), acts as a feeder, and the
stationarity condition on as function of and
gives the ratio = 0.246, in fair accord with the value 0.20
given above. Inclusion of a two-loop is crucial for the agreement. \\
Keywords: confinement scale, QCD effective action, minimality condition,
-field.Comment: LaTex file, 12 pages on dv
The Dimensions of Field Theory : From Particles to Strings
This is an editorial summary of the contents of a Book comprising a set of
Articles by acknowledged experts dealing with the impact of Field Theory on
major areas of physics (from elementary particles through condensed matter to
strings), arranged subjectwise under six broad heads. The Book which emphasizes
the conceptual, logical and formal aspects of the state of the art in these
respective fields, carries a Foreword by Freeman Dyson, and is to be published
by the Indian National Science Academy on the occasion of the International
Mathematical Year 2000. The authors and full titles of all the Articles (33)
are listed sequentially (in the order of their first appearance in the
narration) under the bibliography at the end of this Summary, while a few of
the individual articles to appear in the Book are already available on the LANL
internet.Comment: LaTex file, 24 page
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