Dean Baskin
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drbaskin.bsky.social
Dean Baskin
@drbaskin.bsky.social
Mathematician, professor (Texas A&M). Opinions are my own.
She came to the B/CS no kings protest, so at least she realizes we’re also in the district
November 18, 2025 at 3:15 AM
I tried them for a year and loved them so much I just subscribed for the next ten.
November 18, 2025 at 2:35 AM
The Ivy and Bean books are great! Also Kate DiCamillo has a one-off (I think) called flora and Ulysses, which is about a girl and her friend Ulysses (who is a squirrel that obtains super powers after being sucked into a vacuum)
November 14, 2025 at 9:08 PM
I read Vonnegut’s breakfast of champions when I was 14 and took the same lesson from it. I’ve only recently gotten into discworld and love its moral spine.
November 12, 2025 at 4:23 AM
We started a new topic: eigenvalue counting, working towards the weyl law.
October 23, 2025 at 12:54 PM
On Wednesday we discussed symmetries of the Riemann curvature tensor and introduced the ricci and scalar curvatures.
October 23, 2025 at 12:54 PM
Yesterday we managed to introduce the curvature tensor. (Finally!)
October 21, 2025 at 6:37 PM
We finished the PDE superstructure needed to get the exponential energy decay. Next up: eigenvalue counting
October 21, 2025 at 6:36 PM
We are proving exponential energy decay for the damped wave equation under the geometric control condition. We have proved the resolvent estimate and are working towards the result.
October 18, 2025 at 12:30 AM
After fall break we have introduced manifolds and left the comfort of flat space times behind. We are barreling toward curvature and (finally!) the Einstein equations
October 18, 2025 at 12:29 AM
Today we introduced Christoffel symbols and the covariant derivative
October 9, 2025 at 1:27 AM
We proved that semiclassical defect measures are concentrated on the energy surface and invariant under Hamilton flow. We will start talking about the damped wave equation soon!
October 9, 2025 at 1:27 AM
Today we finally introduced semiclassical defect measures. I am hoping to start talking about the damped wave equation on Wednesday
October 6, 2025 at 8:12 PM
We’re doing general coordinate changes and about to introduce the covariant derivative
October 6, 2025 at 8:11 PM
I want to get to semiclassical measures so I just presented most of the rest of the calculus as a list of properties. I think we will probably use Hörmander’s trick for L2 boundedness, though.
October 3, 2025 at 4:33 PM
Changing coordinates, tangent and cotangent spaces! It’s getting fun!
October 3, 2025 at 4:31 PM
Today we did the composition law for general symbols. I think starting Friday we will restrict our symbol classes quite a bit to make our lives easier.
October 1, 2025 at 4:55 PM
Today we differentiated tensors in inertial frames in special relativity and then spent the rest of class arguing that inertial frames cannot exist in the presence of gravity. Onward!
October 1, 2025 at 4:53 PM
Working toward composition for general symbols.
September 30, 2025 at 2:51 PM
Yesterday we talked about more general tensors, which included a he identification of a finite dimensional vector space with its double dual.
September 30, 2025 at 2:50 PM
Today we discussed one-forms as arising (locally) from differentials of functions and the one-form/vector pairing as directional derivatives. I think we have one more day of general tensors before we finally get to the equivalence principle.
September 27, 2025 at 1:53 AM
Today we proved the Borel lemma and started working toward various composition formulas for symbol classes.
September 27, 2025 at 1:52 AM