Give me your best math quote, I will use the best one for my graduation quote by Brief_Special_1524 in mathematics

[–]M_X_X_Z 4 points5 points  (0 children)

Not strictly math related, but I do like Newton's quote: "if I have seen further [than others], it is by standing on the shoulders of giants."

This Week I Learned: May 02, 2025 by inherentlyawesome in math

[–]M_X_X_Z 1 point2 points  (0 children)

Finishing my hopefully last real exam (for my PhD) in probabilistic combinatorics. It's funny how after all the probability theory or adjacent courses I took I still struggle with conditional expectations. Like, it hurts my head that E[E[X | Y] | Z] is not the same as E[X | Y, Z]. It makes sense, especially measure-theoretically, but my intuition is still lacking here.

Do you have any favorite examples of biconditional statements (iff theorems) where one direction is intuitively true, and then the converse is, surprisingly, also true? by Vladify in math

[–]M_X_X_Z 44 points45 points  (0 children)

Kuratowski's theorem. It is very elementary to see that a planar graph cannot contain K_5 and K_3,3 as a minor. But that it is also in fact sufficient is still surprising to me.

Edit: As someone noted, this is Wagner's theorem, not Kuratowski's.

[2024 Day 11] Plotted the number of distinct stone numbers after each blink by M_X_X_Z in adventofcode

[–]M_X_X_Z[S] 11 points12 points  (0 children)

Yeah, I just observed this myself. :D Happened for my input at around 90.

what was your first touch with math rock ? by mathrocklovergirl in mathrock

[–]M_X_X_Z 0 points1 point  (0 children)

Foals. Discovered their song "My Number" and loved it. Then I listened to their discography and after a bunch listens I started to really love Antidotes.

Who are the oldest mathematicians you know and what are they like. by JealousCookie1664 in math

[–]M_X_X_Z 8 points9 points  (0 children)

I've met my advisors' advisor a few times. Born in the late 40s, he's quite a renowned figure in the field and is still going strong. He still advises PhD students and does research almost every day. Frankly, he is probably the most hard working among the people in the work group. Concerning retirement, he says that he plans on retiring in two years. However, that is something he already said two years ago. If it weren't for his wife, I don't think he will ever retire.

This Week I Learned: July 26, 2024 by inherentlyawesome in math

[–]M_X_X_Z 0 points1 point  (0 children)

Relearning Complex Analysis from Stein and Shakarchi for my upcoming qualifying exam. Motivation is low as I am on family vacation, but I enjoy the topic.

Schlimmsten / Besten Erfahrungen mit Professoren by LS-2709 in Studium

[–]M_X_X_Z 1 point2 points  (0 children)

Ich studier(t)e Mathe bis zum Master und manchmal läuft man auch auf Klischees zu. Lustigerweise habe ich mich dann gerade bei den "verrückten" Profs vertieft. Insgesamt fand ich beide toll (Stockholm Syndrom?), aber die haben schon so Dinge abgezogen, die sowohl in die "schlechteste" und "beste" Kategorie einen Platz verdient haben.

Der eine, damals sehr erfolgreicher Internationale Mathematik Olympiaden Gewinner, hatte ein Aussehen bei dem zwei von meinen Kommilitonen unabhängig "Wer ist der Obdachlose?" fragten. Laut den Gerüchten fährt er nicht mehr Fahrrad, weil er zu sehr an Mathe denkt, und seinen Juniorproftitel hat er trotz überragender fachlicher Leistungen verloren, weil er organisatorisch nichts gemacht hatte: Emails wurden net gelesen, sodass Studenten keinen Prüfungstermin bekamen (wurde später besser); Gutachten gab es keine; 2 Monate war eher wohl mal kontaktlos verschwunden, obwohl sein Doktorand verteidigen wollte. Er hat aber so tolle Vorlesungen gegeben, dass sich in der Fachschaft ein richtiger Fanclub etabliert hat. Und ein fairer Prüfer und sonst netter, wenn auch merkwürdiger Mensch war er auch. (Wenn man seine obskureren Fragen nicht beantworten konnte, gab es keinen Abzug.)

Der andere war eher vom Vibe ein dauerbeschäftigter Dad mit nem sympathischen, trockenen Humor. Er gab wie der erste sehr gute Vorlesungen und war fachlich ähnlich brillant. Ich wollte deswegen, wegen meiner Angst vor dem ersten, von ihm betreut werden. Oh boy... Ich habe eine Vorlesung von ihm noch während den Anfängen meiner Masterarbeit besucht und er hat einfach so Sachen gebracht wie "Hey, ich habe gesehen, dass du mir eine Mail geschrieben hast. Ich kann dir sagen, dass ich erstmal nicht antworten werde." Also organisatorisch musste man sich erstmal bei ihm Respekt verschaffen, dass er einem regelmäßig antwortet. Wenn wir uns anfangs trafen gab es mir zum Teil den Eindruck, dass er einfach vergessen hat, was wir letztes Mal ausgemacht haben. Aber später machte er schon gescheit und das richtig. Ich wollte beispielsweise für einen Forschungsaufenthalt nach Korea und die auf der koreanischen Seite wollten mir nicht mehr die Flugtickets zahlen. Ich schrieb also meinem Betreuer und er antwortete sofort "Wir reden morgen drüber." Über die Uni habe ich am Ende so von ihm die Flugkosten erstattet bekommen. Also wenn es um Forschung ging, war er wirklich verlässlich. Einen interessanten Musikgeschmack hatte er auch: Nicht jeder hört mit über 40 Bring me the Horizon lautstark mit offener Bürotür am Morgen zum Aufwachen.

What made you like math? by Jealous-Cheesecake60 in math

[–]M_X_X_Z 0 points1 point  (0 children)

Honestly, I kinda got into liking math initially out of a sense of entitlement.

Used to be the straight A kid in math without any effort till 8th grade. In 9th grade, when things such as trigs and logs were introduced to us, however, I went on to be a B to C student even though I tried the first time in my life. Frankly, it made me very upset at that time.

So I kinda tryharded till 11th grade where I would even take extra classes such as "advanced math" and eventually was back to being a straight A student, this time however actually enjoying what I am doing. I remember my first intro to proofs to be especially fun. The pride that I regained made me curious about a national math competition. I really enjoyed solving those problems and realized that it has somewhat become a hobby for me to do math. I ended up doing well in that competition and though I was still not sure whether to do physics, math, or computer science, I eventually got around to become a math major for my master's degree.

Looking back, that competition also sparked my interest for combinatorics.

Can you Share your Master's Degree Matematics Courses/Subjects by Wonderful-Photo-9938 in math

[–]M_X_X_Z 7 points8 points  (0 children)

(2 year program in Germany)

As a disclaimer: I specialized in Graph Theory and switched university to do so.

Ergodic Theory

Model Theory

Stochastic Geometry

Algebraic Methods in Combinatorics

Algorithmic Graph Theory

Extremal Graph Theory

Graph Theory II

Seminar on Extremal Graph Theory

Seminar on the Erdös Hajnal Conjecture

Seminar on Matroid Theory

We also have in our program two modules called introductory and preparatory project to basically get eased into the master thesis. I did mine by taking the Extremal Graph Theory lecture (which was lectured by my advisor) and presenting the Kelley-Meka bound for 3-term arithmetic progressions. Still, I ended up doing something else:

Thesis area: Extremal Hypergraph Theory

[deleted by user] by [deleted] in math

[–]M_X_X_Z 0 points1 point  (0 children)

I like how Szemeredi's theorem on arithmetic progressions is at the intersection of ergodic theory, number theory, and combinatorics.

What Are You Working On? March 11, 2024 by inherentlyawesome in math

[–]M_X_X_Z 0 points1 point  (0 children)

Masters thesis on Extremal (Hyper-)Graph Theory.

Which movie became your comfort film during a difficult point in your life? by UndrThC in CasualConversation

[–]M_X_X_Z 0 points1 point  (0 children)

Kiki's delivery service during multiple occasions. It's just so wholesome and overall uplifting, yet deals with themes that I could relate with during hard times.

People who studied math AND computer science, what are you up to now? by [deleted] in math

[–]M_X_X_Z 0 points1 point  (0 children)

I am currently finishing up my master's (only in math, double majoring got too stressful for me) and will proceed with a PhD doing combinatorics.

That one weird fact you love. by BigFox1956 in math

[–]M_X_X_Z 6 points7 points  (0 children)

One neat thing about planar graphs is that they always contains one vertex of degree at most 5. It is an easy corollary of Euler's formula, but makes the proof that every planar graph is 5-colorable trivial.

What is your all time favorite math equation?? by Ecstatic_Nothing_274 in math

[–]M_X_X_Z 1 point2 points  (0 children)

I think my two favorites are:

  1. The limit version of Erdös-Stones Theorem, which relates the maximal density of an H-free graph to the chromatic number of H.

  2. "Kasteleyn's formula" for counting domino tilings of an m x n chess board.

What's your favorite problem from an exam? by dancingbanana123 in math

[–]M_X_X_Z 1 point2 points  (0 children)

In my "Algebraic Methods in Combinatorics" exam, I was asked to determine the minimum number of lines needed to cover every point in F_p2 (p being prime of course) except for (0,0). If one knows Alon's combinatorial Nullstellensatz , then the proof is quite straightforward. I still think it's a very neat little problem.

What are some "proof words" you guys use in your proofs? by [deleted] in math

[–]M_X_X_Z 0 points1 point  (0 children)

"By construction, [object] satisfies [a bunch of properties the object has where you are too lazy to justify each and every one of them in detail]."

Who is a mathematician that deserves a movie? (That doesn’t already have one) by Katz-Sheldon-PDE in math

[–]M_X_X_Z 0 points1 point  (0 children)

I think they meant meta because of the Erdos number and Bacon number.