5,536 research outputs found
Interpretable Transformations with Encoder-Decoder Networks
Deep feature spaces have the capacity to encode complex transformations of
their input data. However, understanding the relative feature-space
relationship between two transformed encoded images is difficult. For instance,
what is the relative feature space relationship between two rotated images?
What is decoded when we interpolate in feature space? Ideally, we want to
disentangle confounding factors, such as pose, appearance, and illumination,
from object identity. Disentangling these is difficult because they interact in
very nonlinear ways. We propose a simple method to construct a deep feature
space, with explicitly disentangled representations of several known
transformations. A person or algorithm can then manipulate the disentangled
representation, for example, to re-render an image with explicit control over
parameterized degrees of freedom. The feature space is constructed using a
transforming encoder-decoder network with a custom feature transform layer,
acting on the hidden representations. We demonstrate the advantages of explicit
disentangling on a variety of datasets and transformations, and as an aid for
traditional tasks, such as classification.Comment: Accepted at ICCV 201
Three-dimensional quantum geometry and black holes
We review some aspects of three-dimensional quantum gravity with emphasis in
the `CFT -> Geometry' map that follows from the Brown-Henneaux conformal
algebra. The general solution to the classical equations of motion with anti-de
Sitter boundary conditions is displayed. This solution is parametrized by two
functions which become Virasoro operators after quantisation. A map from the
space of states to the space of classical solutions is exhibited. Some recent
proposals to understand the Bekenstein-Hawking entropy are reviewed in this
context. The origin of the boundary degrees of freedom arising in 2+1 gravity
is analysed in detail using a Hamiltonian Chern-Simons formalism.Comment: 39 pages, Latex, no figures. Invited talk at the Second Meeting
"Trends in Theoretical Physics", held in Buenos Aires, December, 1998. v2:
References added and minor corrections. v3: An incorrect statement about the
sign of the Chern-Simons level erased. Extended (and in some cases modified)
discussions in most sections. References adde
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