5,750 research outputs found
Stepping theories of active logic with two kinds of negation
This paper formulates a stepping theory formalism with two kinds of negation dealing with one of the areas of Active Logic, a new kind of logic aimed at performing practical tasks in real time knowledge-based AI systems. In addition to the standard logical negation, the proposed formalism uses the so-called subjective negation interpreted as inability to arrive at some conclusion through reasoning by a current time. The semantics of the proposed formalism is defined as an~argumentation structure
Quantum limits of super-resolution in reconstruction of optical objects
We investigate analytically and numerically the role of quantum fluctuations
in reconstruction of optical objects from diffraction-limited images. Taking as
example of an input object two closely spaced Gaussian peaks we demonstrate
that one can improve the resolution in the reconstructed object over the
classical Rayleigh limit. We show that the ultimate quantum limit of resolution
in such reconstruction procedure is determined not by diffraction but by the
signal-to-noise ratio in the input object. We formulate a quantitative measure
of super-resolution in terms of the optical point-spread function of the
system.Comment: 23 pages, 7 figures. Submitted to Physical Review A e-mail:
[email protected]
Localisation and mass generation for non-Abelian gauge fields
It has been suggested recently that in the presence of suitably "warped"
extra dimensions, the low-energy limit of pure gauge field theory may contain
massive elementary vector bosons localised on a "brane", but no elementary
Higgs scalars. We provide non-perturbative evidence in favour of this
conjecture through numerical lattice measurements of the static quark-antiquark
force of pure SU(2) gauge theory in three dimensions, of which one is warped.
We consider also warpings leading to massless localised vector bosons, and
again find evidence supporting the perturbative prediction, even though the
gauge coupling diverges far from the brane in this case.Comment: 27 pages; small clarifications adde
- …