Andrés R. Vindas Meléndez

Prof. Andrés with group 1 of students.

Prof. Andrés with group 2 of students.

Today was our last day of our research experience and I am extremely proud of my summer research students @hmc.edu!

Group one (Tito Cuchilla ‘26, Joseph Hound @claremontgraduateu.bsky.social, Cole Plepel ‘27, Louis Ye ‘27)

Group two (Cameron Ake ‘28, Spencer Lewis ‘28, Amanda Louie ‘28)

Equivariant volumes of symmetric edge polytopes The symmetric edge polytope ($\mathrm{SEP}$) of a finite simple graph $G$ is a centrally symmetric lattice polytope whose vertices are defined by the edges of the graph. Among the information encoded ...

New preprint announcement! This is my FIRST paper with @hmc.edu students and a @claremontgraduateu.bsky.social grad student! Very proud of this paper and the students who worked with me this summer.

“Equivariant volumes of symmetric edge polytopes”
arxiv.org/abs/2507.18846

The Surprising Math and Physics behind the 2026 World Cup Soccer Ball Here’s how the new tetrahedron-based design for the “Trionda” soccer ball may affect next year’s big game

ok i am aggressively not a sports person, but this story by @dodecalemma.bsky.social is so cool! and the graphics were fun to work on :) www.scientificamerican.com/article/the-...

Squirrels LOVE octahedra.

What is your favorite shape & why? For HMC math prof
@arvm.bsky.social it's a permutahedron, a symmetrical, convex polytope that exhibits many special properties. Read more about Vindas Meléndez's favorite shape & the key it holds to big mathematical mysteries on @sciam.bsky.social. uqr.to/arvm-sm.

Yuan Zhou talks at the #mip2025 about how to estimate the solid angle of d-dimensional cones, which corresponds to the proportion of Rd occupied by them, and which does not has a known closed formula for d > 3.

1/N

Seems like today was a good day to be too busy to check social media during work hours

#MathSky there's a new online open-access (and free) journal for mathematics and fiber arts: Interlace. Now accepting manuscripts! Editors-in-Chief: sarah-marie belcastro and Carolyn Yackel. 🧶
www.interlace-journal.org

A New Definition of Pain FoxTrot by Bill Amend | May 4, 2025

Happy Star Wars day! May the Fourth be with you!
foxtrot.com/2025/05/04/a...

No, only in captivity.

Release Release_1_6_11 · 4ti2/4ti2 What's Changed .github/workflows/ci-sage.yml: Update, use passagemath, remove cygwin by @mkoeppe in #45 Modernize the build system / drop support for old toolchains by @orlitzky in #44 New Contr...

New release of 4ti2, the package for algebraic, geometric and combinatorial problems on linear spaces. This is a maintenance release with no new features.
github.com/4ti2/4ti2/re...
#FOSS #MathSky

The Ehrhart polynomial of a matroid specializes to the beta invariant We show that the linear coefficient of the Ehrhart polynomial of a matroid base polytope evaluated at $t-1$ is equal to, up to normalization, the $β$-invariant of the matroid. This yields a lattice-po...

New paper with awesome collaborators!
"The Ehrhart polynomial of a matroid specializes to the beta invariant" with Anastasia Chavez (SMC), Galen Dorpalen-Barry (Texas A&M), Luis Ferroni (IAS & UniPi), Fu Liu (UC Davis), and Felipe Rincón (QMUL). #mathsky
arxiv.org/abs/2504.15518

HMC mathematics professor @arvm.bsky.social has co-authored a paper on polynomial properties in polyhedral geometry. Read the full article about Vindas Meléndez's paper on the behavior of local h-polynomials on our news page. uqr.to/hmc-arvm.

Profs. @haydeelindo.bsky.social, @jamiehadd.bsky.social & Talithia Williams share the Institute for Data Science and Social Impact, which will foster interdisciplinary collaboration, advance data science research, & create pathways to apply data-informed methods to real-world issues. uqr.to/iap-dssi

HMC mathematics professor @jamiehadd.bsky.social has been awarded a CAREER grant from the NSF. The grant supports Haddock's desire to be a mentor and increase access in data science for groups that have been historically excluded from research mathematics. uqr.to/haddock-career.

Three actions of D₄: on itself by multiplication, on itself by conjugation, and on its subgroups by conjugation. Action graphs of each are shown.

This week, I recorded 4 new #VisualAlgebra YouTube videos on group actions. I heavily use the following concepts:

1. G-sets
2. Action graphs
3. Group switchboards
4. Fixed point tables.

Interested? I'll give you a preview here. Please share!

#MathSky 🧵👇1/16

My submission for Day 15 of
@ayliean.bsky.social's #MathArtMarch: Triangle!

My submission for Day 17 of
@ayliean.bsky.social's #MathArtMarch: Symmetry!

My submission for Day 16 of
@ayliean.bsky.social's #MathArtMarch: Connected!

💛💛💛

#mathsky

It’s me 😅
Love the math I get to do with amazing collaborators!

www.hmc.edu/about/2025/0...

… y feliz cumpleaños!🎂

Good! …though I’m still salty it happened in the first place.

Today would have been the 104th birthday of Brazilian mathematician Marília Chaves Peixoto, the 1st woman in Brazil to earn a PhD in math, and a researcher into the conditions for stable fluid flow over a surface. She passed away in 1961 at the age of just 39.

#WomeninSTEM #MathSky #HistSci 🧪🧮

A dear friend wrote a thing about me. Thank you, @yarntheory.bsky.social, for this post but mostly for your friendship. ❤️

on approaching hard problems Friends, colleagues, and lovers of words, I usually use this space to talk about books, but today I want to tell you about my friend Adriana Salerno. Like...

My friend @mathyadriana.bsky.social lost her job last week, and I want you to know the story:

buttondown.com/yarntheory/a...

Me🤦🏻‍♂️: name’s not correct in the doc. My last names are V_ M_ & only shows M_

Tax assessor: I took name from deed

🤦🏻‍♂️: That has my FULL name

T: *checks deed* you should’ve hyphenated. I’ll change it if you insist

🤦🏻‍♂️: No I shouldn’t have bc my name has NO HYPHEN. Yes I insist because I want MY NAME.

Last night I found out that the NSF math postdoctoral fellowship I applied for is being deleted because it does not comply with Trump’s executive orders on DEI in the federal government. I’m going to answer some FAQs and share some thoughts about this ordeal in this thread 1/n

23-501: Federal Grant Opportunity Package(s) Deleted The following grant opportunity package(s) were deleted: Funding Opportunity Number: 23-501 Funding Opportunity Title: Mathematical and Physical Sciences Ascending Postdoctoral Research Fellowships Opportunity Package ID: PKG00277218 Agency Code: NSF Agency: National Science Foundation Deleted Date: Feb 08, 2025 Deletion Comments: Opportunity deleted

Y’all they cancelled the NSF MPS Ascend Program after encouraging underrepresented folks to only apply to it and not both the Ascend and the MSPRF. This is astronomically fucked up for many grad students and postdocs of color in math. #MathSky