4,075 research outputs found
Topological field theory of dynamical systems
Here, it is shown that the path-integral representation of any stochastic or
deterministic continuous-time dynamical model is a cohomological or Witten-type
topological field theory, i.e., a model with global topological supersymmetry
(Q-symmetry). As many other supersymmetries, Q-symmetry must be perturbatively
stable due to what is generically known as non-renormalization theorems. As a
result, all (equilibrium) dynamical models are divided into three major
categories: Markovian models with unbroken Q-symmetry, chaotic models with
Q-symmetry spontaneously broken on the mean-field level by, e.g., fractal
invariant sets (e.g., strange attractors), and intermittent or self-organized
critical (SOC) models with Q-symmetry dynamically broken by the condensation of
instanton-antiinstanton configurations (earthquakes, avalanches etc.) SOC is a
full-dimensional phase separating chaos and Markovian dynamics. In the
deterministic limit, however, antiinstantons disappear and SOC collapses into
the "edge of chaos". Goldstone theorem stands behind spatio-temporal
self-similarity of Q-broken phases known under such names as algebraic
statistics of avalanches, 1/f noise, sensitivity to initial conditions etc.
Other fundamental differences of Q-broken phases is that they can be
effectively viewed as quantum dynamics and that they must also have
time-reversal symmetry spontaneously broken. Q-symmetry breaking in
non-equilibrium situations (quenches, Barkhausen effect, etc.) is also briefly
discussed.Comment: 18 pages, 4 figures, published versio
Research, development and application of the innovational technology of high quality pump-compressor pipes production from sections
The innovational technology of high-strength, cold- and corrosion-resistant pump-compressor pipes from sections was developed. It includes the reduction process inside three-high stand of screw rolling before piercing in the «80» pipe-rolling mill line in OAO SinTZ. The special attention is paid to the questions of fine-grained steel production and final tubes quality. It is shown that new technology is efficient from the point of tube production of high level mechanical properties
Exact singlet bond ground states for electronic models
We have proposed several 1D and 2D electronic models with the exact ground
state. The ground state wave function of these models is represented in terms
of "singlet bond" functions consisting of homopolar and ionic configurations.
The Hamiltonians of the models include the correlated hopping of electrons,
pair hopping terms and the spin interactions. One of the 1D models demonstrates
spontaneous breaking of the translational symmetry. We studied also the model
describing the transition point between the phases with and without an
off-diagonal long-range order.Comment: 4 pages, 2 figures, Revte
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