  This white paper describes the LSST Dark Energy Science Collaboration (DESC),
whose goal is the study of dark energy and related topics in fundamental
physics with data from the Large Synoptic Survey Telescope (LSST). It provides
an overview of dark energy science and describes the current and anticipated
state of the field. It makes the case for the DESC by laying out a robust
analytical framework for dark energy science that has been defined by its
members and the comprehensive three-year work plan they have developed for
implementing that framework. The analysis working groups cover five key probes
of dark energy: weak lensing, large scale structure, galaxy clusters, Type Ia
supernovae, and strong lensing. The computing working groups span cosmological
simulations, galaxy catalogs, photon simulations and a systematic software and
computational framework for LSST dark energy data analysis. The technical
working groups make the connection between dark energy science and the LSST
system. The working groups have close linkages, especially through the use of
the photon simulations to study the impact of instrument design and survey
strategy on analysis methodology and cosmological parameter estimation. The
white paper describes several high priority tasks identified by each of the 16
working groups. Over the next three years these tasks will help prepare for
LSST analysis, make synergistic connections with ongoing cosmological surveys
and provide the dark energy community with state of the art analysis tools.
Members of the community are invited to join the LSST DESC, according to the
membership policies described in the white paper. Applications to sign up for
associate membership may be made by submitting the Web form at
http://www.slac.stanford.edu/exp/lsst/desc/signup.html with a short statement
of the work they wish to pursue that is relevant to the LSST DESC.
