Pacific Postdoc Program

Application: Pacific Postdoc Program 

The Dark Universe Science Center (DUSC) at the University of Washington is currently accepting applications for the Pacific Postdoc Program,  PPP @ DUSC.  The four selected postdocs for each program will be supported by the Simons Foundation to spend four weeks at the University of Washington in Seattle collaborating with the other program attendees and local researchers to advance the theme of the program.   

To apply for the Fall 2026 program, From Streams to the Forest: Testing Dark Matter on Small Scales (Oct 26-Nov 20), submit an application by July 15, 2026.  We anticipate acceptance decisions by early August.

From Streams to the Forest: Testing Dark Matter on Small Scales

The clustering of matter on subgalactic scales is one of the most powerful discriminants of dark matter physics: warm, fuzzy, self-interacting, and other dark matter scenarios all leave their imprint on the abundance and structure of low-mass halos. Remarkably, a diverse and rapidly maturing set of astrophysical methods is now reaching the sensitivity to test these predictions -- satellite populations and perturbations to stellar streams (both of which Rubin will expand dramatically), the Lyman-alpha forest, and strong-lensing flux ratios.  Highly magnified stars, fast radio bursts, and precise astrometry may probe even smaller dark matter structures.  Progress requires connecting particle models of dark matter to the nonlinear small-scale observables that are often complicated by baryonic physics, making this a problem that spans theory, simulation, and observation. The Pacific Postdoc Program will convene researchers working across these approaches to small-scale structure. Successful applicants will spend four weeks (Oct 26-Nov 20) at the Dark Universe Science Center at the University of Washington, engaging with the other selected PPP participants and local UW scientists.  The program will also include a retreat to the Whiteley Center in the San Juan Islands, providing a focused setting for collaborative progress on these challenges.

Program leads: Matthew McQuinn, Miguel Morales, and Nora Shipp

Past PPP programs:

Spring 2026 -- Robust Inference from Cosmological Clustering

We live in a rich time for cosmological datasets, with upcoming maps from Euclid, Rubin, SPHEREx, and the Simons Observatory, building on the previous generation of weak lensing and CMB surveys as well as ongoing work with DESI. Strikingly, many existing data sets yield discrepant parameter values within the LCDM model that seem challenging to explain with plausible model extensions. This tension marks a potential turning point: although statistical constraints continue to tighten, cosmological inference may stall without new approaches to reconciling discrepancies, verifying consistency across data sets, and understanding the nonlinear (astro)physics that limits usable wavenumbers. The Pacific Postdoc Program will convene researchers working on the theoretical, statistical, and observational aspects of cosmological clustering. Successful applicants will spend four weeks (March 30 – April 24, 2026) at the Dark Universe Science Center at the University of Washington, engaging with PPP postdocs and local UW scientists, with a retreat to the Whiteley Center in the San Juan Islands providing a setting for collaborative progress on these challenges.

Program leads: Marilena Loverde and Matthew McQuinn. 

Fall 2025 -- Axions: Theory to Experiment

The QCD axion and axion-like-particles more generally are some of the best-motivated candidates for physics beyond the Standard Model. They are a generic prediction of string theory and can lead to a rich plethora of experimental signatures at colliders, table top experiments and in cosmology. As a result, axions provide a rare and interesting connection between formal theory, phenomenology and the experimental program in particle and astro-particle physics.This Pacific Postdoc Program seeks to bring together postdocs working on diverse aspects of axion physics. Successful applicants will be hosted by the Dark Universe Science Center at the University of Washington for 4 weeks (Oct 5 - Nov 1 2025) to interact with other PPP postdocs, as well as local faculty, postdocs and graduate students at the UW.   The visit includes a retreat to the Whiteley Center in the San Juan Islands.

Program leads: Masha Baryakhtar (mbaryakh@uw.edu) and Isabel Garcia Garcia (isabelgg@uw.edu). Experimental advisor: Gray Rybka