287,938 research outputs found
q-Deformed Brownian Motion
Brownian motion may be embedded in the Fock space of bosonic free field in
one dimension.Extending this correspondence to a family of creation and
annihilation operators satisfying a q-deformed algebra, the notion of
q-deformation is carried from the algebra to the domain of stochastic
processes.The properties of q-deformed Brownian motion, in particular its
non-Gaussian nature and cumulant structure,are established.Comment: 6 page
A Variational Framework for Structure from Motion inOmnidirectional Image Sequences
We address the problem of depth and ego-motion estimation from omnidirectional images. We propose a correspondence-free structure-from-motion problem for sequences of images mapped on the 2-sphere. A novel graph-based variational framework is first proposed for depth estimation between pairs of images. The estimation is cast as a TV-L1 optimization problem that is solved by a fast graph-based algorithm. The ego-motion is then estimated directly from the depth information without explicit computation of the optical flow. Both problems are finally addressed together in an iterative algorithm that alternates between depth and ego-motion estimation for fast computation of 3D information from motion in image sequences. Experimental results demonstrate the effective performance of the proposed algorithm for 3D reconstruction from synthetic and natural omnidirectional image
Conformal Symmetry of Relativistic and Nonrelativistic Systems and AdS/CFT Correspondence
The nonlinear realization of conformal so(2,d) symmetry for relativistic
systems and the dynamical conformal so(2,1) symmetry of nonrelativistic systems
are investigated in the context of AdS/CFT correspondence. We show that the
massless particle in d-dimensional Minkowski space can be treated as the system
confined to the border of the AdS_{d+1} of infinite radius, while various
nonrelativistic systems may be canonically related to a relativistic (massless,
massive, or tachyon) particle on the AdS_2 X S^{d-1}. The list of
nonrelativistic systems "unified" by such a correspondence comprises the
conformal mechanics model, the planar charge-vortex and 3-dimensional
charge-monopole systems, the particle in a planar gravitational field of a
point massive source, and the conformal model associated with the charged
particle propagating near the horizon of the extreme Reissner-Nordstrom black
hole.Comment: 21 pages, typos corrected, refs and note adde
On presymplectic structures for massless higher-spin fields
A natural presymplectic structure for non-Lagrangian equations of motion
governing the dynamics of free higher-spin fields in four-dimensional anti-de
Sitter space is proposed. This presymplectic structure is then used to the
derivation of the conserved currents associated with the relativistic
invariance and to the construction of local functionals of fields that are
gauge invariant on shell.Comment: 28 pages; V2 - a section on weak Lagrangians and some references
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