Cosmic Structure SIG Seminar — 17 July 2026

The Cosmic Structure SIG will hold a virtual seminar on 17 July 2026 at 10:00am PT / 1:00pm ET. Sujeong Lee of Ohio University will present Constraints on Dynamical Dark Energy from the Full Dark Energy Survey.

Lee examines the w0-wa parameterization using the full six-year Dark Energy Survey dataset, combining growth and geometric probes — supernovae, BAO, and weak lensing and galaxy clustering (3x2pt) — within a single survey. The DES-only combination yields the tightest such constraints using multiple probes from any single survey.

Adding external CMB and DESI BAO data produces a 3.0-sigma deviation from a cosmological constant, with the best-fit consistently favoring w0 > -1 and wa < 0. Because DES relies on different probes and systematics than DESI, it provides an independent cross-check on recent hints for dynamical dark energy.

Lee will discuss how to interpret these results and what they imply for Stage IV surveys, realizing the multi-probe dark energy program envisioned at the inception of DES.

United States, Ohio

des, dark energy, w0-wa, sujeong lee, ohio university, supernovae, bao, weak lensing, galaxy clustering, desi bao