691 research outputs found
Unlocking the Axion-Dilaton in 5D Supergravity
We revisit supersymmetric solutions to five dimensional ungauged N=1
supergravity with dynamic hypermultiplets. In particular we focus on a
truncation to the axion-dilaton contained in the universal hypermultiplet. The
relevant solutions are fibrations over a four-dimensional Kahler base with a
holomorphic axion-dilaton. We focus on solutions with additional symmetries and
classify Killing vectors which preserve the additional structure imposed by
supersymmetry; in particular we extend the existing classification of solutions
with a space-like U(1) isometry to the case where the Killing vector is
rotational. We elaborate on general geometrical aspects which we illustrate in
some simple examples. We especially discuss solutions describing the
backreaction of M2-branes, which for example play a role in the black hole
deconstruction proposal for microstate geometries.Comment: 48 pages + appendices, 5 figure
FLUX SWITCHING IN MULTIPATH CORES REPT. 2
Flux switching in multipath magnetic core
Trifocal Relative Pose from Lines at Points and its Efficient Solution
We present a new minimal problem for relative pose estimation mixing point
features with lines incident at points observed in three views and its
efficient homotopy continuation solver. We demonstrate the generality of the
approach by analyzing and solving an additional problem with mixed point and
line correspondences in three views. The minimal problems include
correspondences of (i) three points and one line and (ii) three points and two
lines through two of the points which is reported and analyzed here for the
first time. These are difficult to solve, as they have 216 and - as shown here
- 312 solutions, but cover important practical situations when line and point
features appear together, e.g., in urban scenes or when observing curves. We
demonstrate that even such difficult problems can be solved robustly using a
suitable homotopy continuation technique and we provide an implementation
optimized for minimal problems that can be integrated into engineering
applications. Our simulated and real experiments demonstrate our solvers in the
camera geometry computation task in structure from motion. We show that new
solvers allow for reconstructing challenging scenes where the standard two-view
initialization of structure from motion fails.Comment: This material is based upon work supported by the National Science
Foundation under Grant No. DMS-1439786 while most authors were in residence
at Brown University's Institute for Computational and Experimental Research
in Mathematics -- ICERM, in Providence, R
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