I just finished calling into a DES telecon for the analysis group working on analyzing galaxy clustering and weak lensing to test for physics beyond the standard cosmological model. Because I live in California, time
zones mean that most DES telecons are early in the morning for me, so I usually call in from home. Sometimes I have an audience. 🐱 #DEST4TD

Thanks to Jessie Muir (SLAC National Accelerator Laboratory, Stanford University) for today's DES thought for the day! ... See MoreSee Less

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The Dark Energy Survey

5 days ago

#DESimages (merging galaxies, credit: Cyrille Doux and Erin Sheldon) ... See MoreSee Less

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The Dark Energy Survey

2 weeks ago

Neutron stars are incredibly dense. A teaspoon of neutron star has the same weight as nearly 17,000 Empire State Buildings. #DarkBites

Picture: Chihway Chang ... See MoreSee Less

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The Dark Energy Survey

2 weeks ago

#DESimages (NGC 7424, credit: Robert Gruendl) ... See MoreSee Less

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The Dark Energy Survey

2 weeks ago

I'm preparing a talk on DES cosmology results. It's hard to choose what to show - we have made so much exciting progress in the past couple of years! #DEST4TD

Thanks to Jonathan Blazek (UC Berkeley) for today's DES thought for the day!

Check out our updated webpage containing all of our 200+ DES papers! 😮

dbweb5.fnal.gov:8080/DESPub/app/PB/pub/pbpublished ... See MoreSee Less

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News

Scientists Leverage HPC and AI to Wrangle the ‘Galaxy Zoo’

July 8, 2019 12:00 pm

The research team developed a new approach to classifying these hundreds of millions of galaxies. Instead of relying on crowdsourced classification, the researchers used knowledge from the state-of-the-art Xception neural network, combined with the datasets generated by the Galaxy Zoo project, to train its deep learning models. They then applied the trained model to galactic images from the Dark Energy Survey (DES) – where it achieved a 99.6% accuracy in identifying spiral and elliptical galaxies.

Three sky surveys completed in preparation for Dark Energy Spectroscopic Instrument

July 8, 2019 12:00 pm

It took three sky surveys — conducted at telescopes in two continents, covering one-third of the visible sky, and requiring almost 1,000 observing nights – to prepare for a new project that will create the largest 3-D map of the universe’s galaxies and glean new insights about the universe’s accelerating expansion. This Dark Energy Spectroscopic Instrument (DESI) project will explore this expansion, driven by a mysterious property known as dark energy, in great detail. It could also make unexpected discoveries during its five-year mission.

Multiple Measurements close in on Dark Energy

May 6, 2019 12:00 pm

An extensive analysis of four different phenomena within the universe points the way to understanding the nature of dark energy, a collaboration between more than 100 scientists reveals. Dark energy – the force that propels the acceleration of the expanding universe – is a mysterious thing. It’s nature, write telescope scientist Timothy Abbott from the Cerro Tololo Inter-American Observatory, in Chile, and colleagues, “is unknown, and understanding its properties and origin is one of the principal challenges in modern physics”. Indeed, there is a lot at stake. Current measurements indicate that dark energy can be smoothly incorporated into the theory of general relativity as a cosmological constant; but, the researchers note, those measurements are far from precise and incorporate a wide range of potential variations.

Viewpoint: Dark Energy Faces Multiple Probes

May 1, 2019 12:00 pm

One of the top goals in cosmology today is understanding the dark energy that is responsible for the accelerated expansion of the Universe. Is the dark energy consistent with the cosmological constant of general relativity—representing a constant energy density filling space homogenously? Or can we find deviations from general relativity on cosmological scales that suggest a more complex nature for gravity? Questions like these motivate the current and next generations of surveys that aim to map out ever larger volumes of the Universe, using a wide variety of probes to constrain the properties of dark energy. The Dark Energy Survey (DES) has now derived such constraints from the combined analysis of four canonical observables related to dark energy: supernovae, baryon acoustic oscillations, gravitational lensing, and galaxy clustering [1]. The resulting bounds confirm what we knew from previous studies, which focused on single probes. But the results indicate that this multiprobe approach could allow surveys in the 2020s to improve such constraints by orders of magnitude, possibly bringing us close to solving the dark energy puzzle.

Supernovae, Dark Energy, and the Fate of Our Universe

April 5, 2019 12:00 pm

What’s the eventual fate of our universe? Is spacetime destined to continue to expand forever? Will it fly apart, tearing even atoms into bits? Or will it crunch back in on itself? New results from Dark Energy Survey supernovae address these and other questions. At present, the fabric of our universe is expanding — and not only that, but the its expansion is accelerating. To explain this phenomenon, we invoke what’s known as dark energy — an unknown form of energy that exists everywhere and exerts a negative pressure, driving the expansion. Since this idea was first proposed, we’ve conducted decades of research to better understand what dark energy is, how much of it there is, and how it influences our universe.