Exhibition:Bloody Work: Lexington and Concord 1775
2025-06-05 12:00 - 16:00 (America/Detroit) | William Clements Library
The William L. Clements Library is pleased to announce a forthcoming exhibition in recognition of the 250th Anniversary of the military hostilities that began the American Revolutionary War. The Battles of Lexington and Concord are firmly established in American memory as the culmination of a range of governmental, political, economic, and social tensions that amplified in the decade leading up to 1775. In this exhibit, visitors will have the opportunity to see original historical manuscript letters, documents, newspapers, and artwork that reveal aspects of the bloody work of Empire and individual alike in April 1775.

Among the items on display will be Commander in Chief of the British Army, General Thomas Gage's draft orders for the Concord Expedition, April 18, 1775; a bundle of letters collected by former Sons of Liberty supporter Dr. Benjamin Church, which he secretly turned over to British Army intelligence; letters by Silas Deane, John Hancock, and Rachel Revere; and much more.

Open weekdays from 12-4 pm.

Well-being:Learn to Meditate in 3 days
2025-06-05 12:00 - 13:00 | Off Campus Location
Make meditation part of your goal to strengthen your mental well-being. Discover three core practices—meditation, rejuvenation, and inner connect in just three session.

Meditation is a mindful journey for regulating your mind. It’s like a mental workout, training the mind to focus on a single thought amid the 60,000 that pass through daily. With 3 core practices it cultivates effortless concentration, heightened awareness, and presence in the moment, allowing a shift from thinking to feeling. Meditation also leads to a deeper state of relaxation, regulating the stress response and promoting numerous health benefits.

The session will be guided by a trainer via Zoom meeting for all 3 days from noon to 1 p.m. All U-M students, faculty, and staff are welcome to join at no cost. No prior experience with meditation is required.

Event Details
*When: Every month for 3 days (attending all 3 sessions is recommended)*

The session is Remote over Zoom and upon registration you will have the Zoom MeetingId and Passcode
See Related Links for registration

This wellness program is coordinated by Information Technology and Services (ITS) Teaching & Learning, and is provided at no cost by heartfulness.org.

Join the MCommunity group for email updates – Meditation for wellness

Exhibition:Watcher of the Sky: Making and Remaking the Detroit Observatory
2025-06-05 12:00 - 17:00 | Detroit Observatory
The Detroit Observatory was once a hub of astronomical discovery that put the University of Michigan on the map as a world-class research institution. A century later, it was an abandoned building with an uncertain future. From cornerstone to keystone, from the first director to the people who saved it from destruction, explore the life of a historic observatory 170 years in the making.

"Watcher of the Sky" is being developed by student docents at the Detroit Observatory. They are currently collaborating with a museum design firm on the final version of the exhibit, which will debut in fall 2025. We invite you to check out what they've done so far.

Presented by the Judy and Stanley Frankel Detroit Observatory, part of the Bentley Historical Library.

"Watcher of the Sky" is now on display at the Detroit Observatory (1398 Ann Street, Ann Arbor, 48109). View the exhibit during the Observatory's open hours:
Thursdays, 12-5 pm
Fridays, 12-5 pm

Lecture / Discussion:Deep Learning-Assisted Approximate Bayesian Inference with Applications to Astronomy
2025-06-05 14:00 - 16:00 | West Hall - 438
Approximate Bayesian methods provide a principled means for inference in settings in which exact posterior inference is intractable. In this work, I present methods for variational inference, an approach to approximate Bayesian inference in which an approximation to the posterior is selected by numerical optimization. The approaches and analysis primarily consider amortized variational inference, a class of techniques that leverages deep learning to obtain a mapping from data instances to variational approximations of the posterior. First, I present SMC-Wake, a likelihood-based approach for minimization of the forward KL divergence. This algorithm uses Sequential Monte Carlo (SMC) samplers to construct inexpensive particle approximations for training an inference network. Next, I present a study of neural posterior estimation (NPE) and its objective function, the expected forward KL divergence. This likelihood-free approach to amortized inference averages over large amounts of simulated data from the model to learn mappings from data instances to variational approximations of the posterior. I present an analysis of this approach from the perspective of neural tangent kernel (NTK) theory. Under certain conditions on the variational family and neural network mapping, I show that NPE optimizes a convex functional and reliably converges to a unique solution in the asymptotic infinite-width limit, despite the highly nonconvex nature of neural network optimization landscapes. Finally, I extend these results to posit a novel class of expressive variational families based on linear combinations of basis functions, and propose a procedure to adaptively fit these basis functions to parameterize complex distributions. When targeting the forward KL divergence within this framework, the objective is convex in the variational parameters, but nevertheless allows for practitioners to fit highly multimodal variational approximations to the posterior. We conclude with applications of these methods to difficult problems in astronomy, such as redshift estimation from astronomical images, and the task of detecting blended astronomical spectra.

Presentation:Rigorous Derivation of the Wave Kinetic Equation for beta-FPUT System
2025-06-05 14:00 - 16:00 | Off Campus Location
Abstract:

While the WKE has been rigorously derived for the cubic nonlinear Schrödinger equation in dimensions dge 2 and for the Majda–McLaughlin–Tabak model in d=1, there is still lack of rigorous justification for the beta-FPUT model whose sinusoidal dispersion and unconserved frequency shift pose additional obstacles. In this thesis, we establish the WKE for a reduced evolution equation, removing the nonresonant terms, from the one‑dimensional beta-FPUT chain. We work in the kinetic limit N to infty and beta to 0 under the scaling laws beta=N^{-gamma} with 0<gamma<1. The result holds up to the sub‑kinetic time scale T=N^{-epsilon}min(N, N^{5/4gamma})=N^{-epsilon}T_{kin}^{5/8} for epsilonll1, where T_{kin} represents the kinetic (thermalization) timescale. We also prove a sufficient upper bound for the nonlinearity parameter $beta$ that allows one to perform the canonical transformation on the original evolution equation. This upper bound suggests a scaling between beta and N, which governs the importance of the non-resonant terms in the original equation. By applying the symplectic integrator method, we further develop numerical studies on the beta-FPUT model, comparing the magnitudes of resonant and nonresonant sums across various nonlinearity strengths and particle numbers to verify the predicted beta-threshold.
