22,295 research outputs found
Science Objectives and Early Results of the DEEP2 Redshift Survey
The DEIMOS spectrograph has now been installed on the Keck-II telescope and
commissioning is nearly complete. The DEEP2 Redshift Survey, which will take
approximately 120 nights at the Keck Observatory over a three year period and
has been designed to utilize the power of DEIMOS, began in the summer of 2002.
The multiplexing power and high efficiency of DEIMOS enables us to target 1000
faint galaxies per clear night. Our goal is to gather high-quality spectra of
\~60,000 galaxies with z>0.75 in order to study the properties and large scale
clustering of galaxies at z ~ 1. The survey will be executed at high spectral
resolution, , allowing us to work
between the bright OH sky emission lines and to infer linewidths for many of
the target galaxies (for several thousand objects, we will obtain rotation
curves as well). The linewidth data will facilitate the execution of the
classical redshift-volume cosmological test, which can provide a precision
measurement of the equation of state of the Universe. This talk reviews the
project, summarizes our science goals and presents some early DEIMOS data.Comment: 12 pages, 5 figures, talk presented at SPIE conference, Aug. 200
Learning with Algebraic Invariances, and the Invariant Kernel Trick
When solving data analysis problems it is important to integrate prior
knowledge and/or structural invariances. This paper contributes by a novel
framework for incorporating algebraic invariance structure into kernels. In
particular, we show that algebraic properties such as sign symmetries in data,
phase independence, scaling etc. can be included easily by essentially
performing the kernel trick twice. We demonstrate the usefulness of our theory
in simulations on selected applications such as sign-invariant spectral
clustering and underdetermined ICA
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