Joined January 2015
- Tweets 464
- Following 443
- Followers 3,112
- Likes 2,010
153 Photos and videos
Jun 13
In a couple of weeks, I'll be moving to Boston for my first sabbatical (spending the year with MIT Sloan).
Colleagues and friends in the area or visiting sometime, reach out. I am optimistic that I'll have more spare cycles than usual :)
13
845
Ben Grimmer retweeted
May 26
I spent a year of my PhD stuck on a 2002 problem of Schechtman. GPT 5.5-Pro helped me finish: vector balancing for zonotopes (shadows of a cube)!
For any zonotope Z ⊂ ℝᵈ, v₁,...,vₙ ∈ Z, there are signs x₁,...,xₙ ∈ {-1, 1} with x₁v₁ ... xₙvₙ ∈ O(√d) Z, sharp. [1/4]
11
49
444
40,208
May 19
I'm excited to share some joint work done with @TaeHo_Y00N.
We considered algorithm design for fixed-point problems.
This area models gradient descent, minimax optimization, and more.
Below I give the wild ride of this paper.
Mathematically, it is gorgeous.
4
26
132
10,461
May 19
Taking this duality, one may ask for methods that are self-dual. Recursively building a maximally self-dual method gives a simple fractal arc diagram and a new Fractal Self-Dual Method.
This FSDM nicely balances anytimeness and robustness; see the paper for details.
1
1
8
681
May 19
Discovering these results with TaeHo has been a delightful experience. I learned a lot.
We drew on tools from combinatorics, spectral graph theory, performance estimation, and more. For those interested, the paper is here:
arxiv.org/abs/2605.02231
1
11
646
Ben Grimmer retweeted
May 18
My star postdoc Sarit Khirirat (sites.google.com/view/sarit-…) is leaving my Optimization & Machine Learning Lab (richtarik.org/i_team.html) to become an Assistant Professor in his home country (Thailand).
As you can see, he is completely checked out, enjoying social media (my guess) and matcha at Zed's at KAUST. 😜😎🤟
This means I have an opening for another star postdoc! If you love mathematics, foundations, optimization and machine learning -- and have outstanding track record in highest quality research -- apply!
richtarik.org/i_apply.html
3
14
212
29,680
Ben Grimmer retweeted
"We found that resurrecting the ancient practice of logarithm tables to be useful" -- Terry Tao @ICERM
5
29
398
30,849
Ben Grimmer retweeted
May 8
Walking with Tianjiao and Caleb：Tianjiao will join IBM Research as a Goldstine Fellow before heading to the University of Wisconsin–Madison, and Caleb will join the University of Tennessee, Knoxville as faculty. Congratulations to both!
2
10
643
Ben Grimmer retweeted
May 7
We just put out a 180-page paper on sampling from the SK model! One big surprise we ran into: the Hessian Ascent algorithms investigated for non-convex optimization have been diffusion models in disguise the whole time! arxiv.org/abs/2605.03718
@JuspreetS @oldheneel
8
60
4,383
May 1
Last year, @mateodd25 and Ian McPherson began searching for provably good nonsmooth optimization methods on manifolds.
Oh boy, did I quickly learn the hard subtleties of numerical work on manifolds, especially combined with finicky subgradients.
1
16
1,543
May 1
If you retract/transport vectors by projections or via Taylor approx, you can not trust the resulting subgradients give valid lower bounds.
After a year of pushing, we found a bundle method form that (provably) works despite this.
I'll comment a link if you want to read more.
1
2
520
Ben Grimmer retweeted
Man, Machine, and Mathematics
arXiv:2604.27052
Nonsmooth Riemannian optimization with inexact manifold primitives v...
arXiv:2604.27078
Explainable Artificial Intelligence for Financial Integral Equations...
arXiv:2604.27127
2
9
597
Ben Grimmer retweeted
Apr 22
My lab will present two papers at ICLR 2026 in Rio de Janeiro, Brazil: "Mirror Flow Matching with Heavy-Tailed Priors for Generative Modeling on Convex Domains" and "Adaptive Gradient Descent on Riemannian Manifolds and Its Applications to Gaussian Variational Inference"
1
2
21
2,299