and hey it turns out that the industry is quite happy to pay millions of dollars for open source code! just not to its developers. no, all that money goes to fucking GOOGLE AND MICROSOFT because they're the ones operating the vacuum cleaners. fucking ludicrous state of affairs.

4색 정리 새로운 증명이 arXiv에 올라왔습니다. New proof of the four color theorem by Yuta Inoue, Ken-ichi Kawarabayashi, Atsuyuki Miyashita, Bojan Mohar, Carsten Thomassen, Mikkel Thorup arxiv.org/abs/2603.24880

Just learned that arXiv is becoming independent of Cornell. Statement by arXiv: tech.cornell.edu/arxiv/

I am happy to share my latest work ``Folding Mixed-Integer Linear Programs and Reflection Symmetries'', where I formulate two new presolving techniques for handling symmetries in linear programs and mixed-integer linear programs. Check out the preprint here: lnkd.in/efgYeVSJ lnkd.in/eGpim7U9

📢 #ISMP2027 comes to Amsterdam! The 26th International Symposium on Mathematical Programming will be held July 25–30, 2027. Join researchers from around the world to discuss advances, challenges, and opportunities in the theory and practice of mathematical optimization. 🔗 ismp2027.mathopt.nl #MOS

📚 New Arxiv Paper Title: Circuit Diameter of Polyhedra is Strongly Polynomial Authors: Bento Natura Read more: https://arxiv.org/abs/2602.06958

The order 'objective - constraints - variables' that academic papers use to describe mathematical optimization problems is inconvenient, as it places the objective before you even know what the variables are. Wouldn't 'variables - constraints - objective' be a more natural progression?

130k lines of formal topology in two weeks: Simple and cheap autoformalization for everyone? ~ Josef Urban. arxiv.org/abs/2601.032... #ITP #Mizar #LLMs #Math #Autoformalization

The SCIP 10 optimization suite has many new interesting features and is fully open source. For binaries and downloads, check www.scipopt.org/index.php#do...

📚 New Arxiv Paper Title: Geometry of the Reformulation-Linearization-Technique: Domination of Disjunctions Authors: Hugo A. Hof, Matthias Walter Read more: https://arxiv.org/abs/2511.13805

I shouldn't be surprised by this, but I just learned that Nvidia and AMD both disable FP64 performance units in their consumer cards so scientists and companies have to buy the high end ones at 5-10x the price. It's a valid business model but unfortunate for hobbyists like me who just want to try.

📚 New Arxiv Paper Title: Linear Programming Hierarchies Collapse under Symmetry Authors: Yuri Faenza, V\'ictor Verdugo, Jos\'e Verschae, Mat\'ias Villagra Read more: https://arxiv.org/abs/2511.07766

Does there exist a commonly used public instance benchmark set for robust optimization? Or sets of instances which are frequently used within the literature?

This was hard work but now we are happy! The #BOBILib paper has today been accepted for publication in Mathematical Programming Computation! Here's the final version of the preprint: optimization-online.org/wp-content/u...! And here's the website bobilib.org! Spread the word and use it! :-)

🔄 Updated Arxiv Paper Title: Implied Integrality in Mixed-Integer Optimization Authors: Rolf van der Hulst, Matthias Walter Read more: https://arxiv.org/abs/2504.07209

This is now out, we're super proud to have won the Land-Doig MIP competition prize for our algorithm for mixed-integer quadratic optimization!

passagemath 10.5.27 contains (a preliminary version of) the new package passagemath-cmr, an interface to the Combinatorial Matrix Recognition library by Matthias Walter et al., implementing Seymour's decomposition of TU matrices etc. pypi.org/project/pass... #Python #SageMath #OpenSource #MathSky

After attempting to tune MIR cuts in SCIP for 3.5 days, I understand better why people are willing to pay so much for a commercial MIP solver license.

🔄 Updated Arxiv Paper Title: Sparsity-driven Aggregation of Mixed Integer Programs Authors: Liding Xu, Gioni Mexi, Ksenia Bestuzheva Read more: https://arxiv.org/abs/2502.01192

registration for the 2025 school on column generation is now open www.gerad.ca/colloques/Co... #orms

The bugfix release 9.2.1 of the SCIP Optimization Suite is now available. This brings updates to GCG, PaPILO, SCIP, and SoPlex: - github.com/scipopt/gcg/... - github.com/scipopt/papi... - github.com/scipopt/scip... - github.com/scipopt/sopl... #orms

I recorded my current talk for youtube! If you are interested in linear programming or theoretical computer science, this is for you

The #mip2025 computational competition is open! This year’s topic is finding feasible solutions for MIPs with quadratic functions. Student participation is encouraged and we may separately award outstanding student submissions. For more details, visit www.mixedinteger.org/2025/competi... #orms

I am very pleased to announce that a 1996 paper I wrote on graph coloring and column generation with Anuj Mehrotra was given a "Test of Time" award by the INFORMS Journal of Computing for papers written 1995-1999. The full citation is at pubsonline.informs.org/doi/10.1287/...