Large Synoptic Survey Telescope: Dark Energy Science Collaboration

Abstract

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 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 DESC.3

Cosmological constraints from weak lensing peak statistics with Canada-France-Hawaii Telescope Stripe 82 Survey

“…Such effects, namely weak lensing effects, are closely related to the formation and evolution of foreground structures and the global expansion history of the Universe, and therefore are known to be one of the most promising probes in cosmological studies (e.g., Albrecht et al 2006;Abate et al 2012;Amendola et al 2013;Weinberg et al 2013). The cosmic shear two-point (2-pt) correlation analysis has been demonstrated to be a powerful statistics in extracting weak lensing signals from shape measurements of background galaxies (e.g., Fu et al 2008;Heymans et al 2012;Kilbinger et al 2013;Jee et al 2013;Kitching et al 2014).…”

Interplay between appearance and disappearance channels for precision measurements ofθ23andδ

“…For sin 2 2θ 23 , on the other hand, we use a value which lies roughly in between the current precision achieved at T2K and MINOS and the T2K systematic uncertainty for this parameter, see Refs. [32,74]. Unless otherwise stated, δ is left completely free during marginalization (i.e., no prior is assumed for this parameter).…”

New geometric representations of the CMB two-point correlation function

“…While deep field surveys [3][4][5] aim to unveil the specific nature of dark matter and dark energy, and thus of the energy content of our universe, CMB observations are special in the sense that they provide a unique window to both the physics of the early inflationary universe and of its global shape, i.e., its geometry and topology [6][7][8][9].…”