845,233 research outputs found
Neighboring mapping points theorem
Let f be a continuous map from a metric space X to M. We say that points in a
subset N of X are f-neighbors if there exists a sphere S in M such that f(N)
lies on S and there are no points of f(X) inside of S. We prove that if X is a
unit sphere of any dimension and M is a contractible metric space then there
are two f-neighbors in X such that the distance between them is greater than
one. This theorem can be derived from the fact that for every
non-null-homotopic closed covering C of X there is a set of f-neighbors N in X
such that every member of C contains a point of N.Comment: 7 pages, 1 figur
Neighboring clusters in Bernoulli percolation
We consider Bernoulli percolation on a locally finite quasi-transitive
unimodular graph and prove that two infinite clusters cannot have infinitely
many pairs of vertices at distance 1 from one another or, in other words, that
such graphs exhibit ``cluster repulsion.'' This partially answers a question of
H\"{a}ggstr\"{o}m, Peres and Schonmann.Comment: Published at http://dx.doi.org/10.1214/009117906000000485 in the
Annals of Probability (http://www.imstat.org/aop/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Radiative energy loss of neighboring subjets
We compute the in-medium energy loss probability distribution of two
neighboring subjets at leading order, in the large- approximation. Our
result exhibits a gradual onset of color decoherence of the system and accounts
for two expected limiting cases. When the angular separation is smaller than
the characteristic angle for medium-induced radiation, the two-pronged
substructure lose energy coherently as a single color charge, namely that of
the parent parton. At large angular separation the two subjets lose energy
independently. Our result is a first step towards quantifying effects of energy
loss as a result of the fluctuation of the multi-parton jet substructure and
therefore goes beyond the standard approach to jet quenching based on single
parton energy loss. We briefly discuss applications to jet observables in
heavy-ion collisions.Comment: 34 pages, 15 figure
Radiative Heat Transfer between Neighboring Particles
The near-field interaction between two neighboring particles is known to
produce enhanced radiative heat transfer. We advance in the understanding of
this phenomenon by including the full electromagnetic particle response, heat
exchange with the environment, and important radiative corrections both in the
distance dependence of the fields and in the particle absorption coefficients.
We find that crossed terms of electric and magnetic interactions dominate the
transfer rate between gold and SiC particles, whereas radiative corrections
reduce it by several orders of magnitude even at small separations. Radiation
away from the dimer can be strongly suppressed or enhanced at low and high
temperatures, respectively. These effects must be taken into account for an
accurate description of radiative heat transfer in nanostructured environments.Comment: 22 pages, 9 figures, fully self-contained derivation
Raman scattering mediated by neighboring molecules
Raman scattering is most commonly associated with a change in vibrational state within individual molecules, the corresponding frequency shift in the scattered light affording a key way of identifying material structures. In theories where both matter and light are treated quantum mechanically, the fundamental scattering process is represented as the concurrent annihilation of a photon from one radiation mode and creation of another in a different mode. Developing this quantum electrodynamical formulation, the focus of the present work is on the spectroscopic consequences of electrodynamic coupling between neighboring molecules or other kinds of optical center. To encompass these nanoscale interactions, through which the molecular states evolve under the dual influence of the input light and local fields, this work identifies and determines two major mechanisms for each of which different selection rules apply. The constituent optical centers are considered to be chemically different and held in a fixed orientation with respect to each other, either as two components of a larger molecule or a molecular assembly that can undergo free rotation in a fluid medium or as parts of a larger, solid material. The two centers are considered to be separated beyond wavefunction overlap but close enough together to fall within an optical near-field limit, which leads to high inverse power dependences on their local separation. In this investigation, individual centers undergo a Stokes transition, whilst each neighbor of a different species remains in its original electronic and vibrational state. Analogous principles are applicable for the anti-Stokes case. The analysis concludes by considering the experimental consequences of applying this spectroscopic interpretation to fluid media; explicitly, the selection rules and the impact of pressure on the radiant intensity of this process
The Coherence of Evolutionary Theory with Its Neighboring Theories
Evolutionary theory coheres with its neighboring theories, such as the theory of plate tectonics, molecular biology, electromagnetic theory, and the germ theory of disease. These neighboring theories were previously unconceived, but they were later conceived, and then they cohered with evolutionary theory. Since evolutionary theory has been strengthened by its several neighboring theories that were previously unconceived, it will be strengthened by infinitely many hitherto unconceived neighboring theories. This argument for evolutionary theory echoes the problem of unconceived alternatives. Ironically, however, the former recommends that we take the realist attitude toward evolutionary theory, while the latter recommends that we take the antirealist attitude toward it
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