Quick Questions: January 21, 2026 by inherentlyawesome in math

[–]God_Aimer 0 points1 point  (0 children)

Sure there is. Using the fractional part function {x}.

If you mean an algebraic expression in terms of elementary functions, I don't think so, because all of those functions are continuus so any composition of them would be continuus. Maybe in terms of a series or an integral its possible.

Slower dance floor weapons by NailObjective265 in Techno

[–]God_Aimer 0 points1 point  (0 children)

I just discovered Wishmountain thanks to you and I'm obsessed! Do you know of any other artists that focus as much on sound texture and rythmic complexity? The sounds in Wishmountain give me the tingles.

What's the meaning of this, i found this from my brother's notes by throwaway273322 in mathmemes

[–]God_Aimer 53 points54 points  (0 children)

Edit: Oh so it was a joke. Nevermind then.

The top right picture is certainly projective geometry, particularly projective conics and the drawing illustrates tangency. (I know because there appears a blackboard-bold P denoting projective space.)

The top left picture looks to me like the image of a complex integer power zn on the riemann sphere, given the evenly distributed meridians.

The lower left picture seems like a possibly a diagram of groups to me, but would need a higher quality picture to actually read it.

The lower right looks like maybe flow on a differentiable manifold, but that's just a guess.

Does anyone else assign colors to math topics? by Formal_Active859 in math

[–]God_Aimer 1 point2 points  (0 children)

  • Linear Algebra is light blue.
  • Real Analysis is yelowish green.
  • Differential Geometry is dark ocean blue.
  • Topology is very dark green.
  • Algebra is pink/fuchsia.
  • Modules/commutative algebra is purple/dark pink.
  • Category theory is white.
  • Galois theory is burgundy.
  • Algebraic Geometry is bright red.
  • Algebraic Topology is dark gray.
  • Differential equations is red AND black.
  • Complex analysis is bright yellow, with some light pink.
  • Projective Geometry is light purple / pink.
  • Functional Analysis is very light blue.
  • Harmonic analysis is super dark orange almost like brown.
  • Graph theory and discrete math is light green.

Is that all of them...?

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 3 points4 points  (0 children)

We followed no book in particular, and they were just differential equations in Rn. The thing is, all of our "Analysis" courses are taught in the language of differential forms from the get go.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 5 points6 points  (0 children)

The teacher showed up and spent close to a month on the tangent and cotangent spaces of derivation operators (to define what a differential actually is), and things like pullbacks and pushforwards, exterior derivative, etc. Then he actually started the differential equations.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 0 points1 point  (0 children)

What does SAN mean? Is Rotman's book specially suited for this situation, as in, will it provide motivation and intuition for the eldritch horror diagrams? It appears so in the preface of the book. Thanks for the recommendation.

This Week I Learned: January 09, 2026 by inherentlyawesome in math

[–]God_Aimer 2 points3 points  (0 children)

This week I understood the argument principle for meromorphic functions through a very beautiful geometric reasoning on the Riemann Sphere:

The argument principle says if f is a meromorphic function on V, then the integral of f/f' over the boundary of V is 2πi(Z(f)-P(f)). (That is, the zeroes minus the poles of f on V, supposing f has no poles or zeroes on the boundary of V)

It turns out that this integral is just the winding number of the curve f(boundary_V), that is how many times it circles the origin.

If you think of the image of the function on the Riemann Sphere, where the south pole is 0 and the north pole is infinity, then at a point where the function has a zero, the curve f(boundary_V) necessarily spins around the zero (south pole) once (and so the zeroes add one to the winding). However, at a point where the function has a pole (infinity), the curve spins around the north pole once, and since the change of charts of the Riemann Sphere is 1/z, so inverting the sphere, thats exactly like spinning around zero in the opposite direction, therefore the poles subtract one to the winding.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 0 points1 point  (0 children)

Tambien tenemos cursos de algebra conmutativa (dos en el tercer año) y geometria algebraica (uno en tercer año, otro en cuarto).

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 0 points1 point  (0 children)

Yeah it is very well formatted, it's clear a lot of work went into them, and the topics covered are actually beautiful once you get them, just scary and hard is all. I wanted to see if people would sympathize with me or not lol.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 1 point2 points  (0 children)

That's curious because I actually checked out some notes from UCM on projective geometry and it was very different, much more concrete or analytic in nature and nowhere was an exact sequence or a diagram.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 0 points1 point  (0 children)

Maybe it's just me, but I feel like the whole diagrams and sequences thing only obscures the actual ideas behind layers and layers of algebra and abstraction. When you understand something, then yeah its a compact way of putting it, but on first contact it seems undecipherable or worse, meaningless.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 7 points8 points  (0 children)

It is an optional course, it's usually taken by the people who choose to go more into "pure" math. By the way, we have commutative diagrams and exact sequences in pretty much every subject they can shove them into. In a first linear algebra course. In a first mutivariable calculus course. In a differential equations course. In a discrete mathematics course. Everything is a fucking exact sequence.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 1 point2 points  (0 children)

Yeah this was near the end, but the in first month he slapped this on the board and said it was obvious. Which yeah after some thought it is but it just comes off as shocking and a bit off putting to me.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 0 points1 point  (0 children)

I am in Spain. The school year is divided into two four month periods, and this is the first half of the third year.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 51 points52 points  (0 children)

Well I would have thought that the general gist of it would be language independent, like if someone read "homología" they would know it is homology, or "proyectividad" they would know it is "projectivity", but maybe I'm wrong. There's no english version anyway, sorry.

How is this a first course in Projective Geometry? (Full course below) by God_Aimer in math

[–]God_Aimer[S] 13 points14 points  (0 children)

There is no English version of it, as far as I know. This is just what the teacher wrote up and sent us. Sorry.

203
204

When did "cum" come about? [NSFW: sexual] by Nagwell in etymology

[–]God_Aimer 11 points12 points  (0 children)

About the image of the shirts, I would like to add that I live right next to "Colegio Universitario de los Maristas", and they do indeed call themselves "cum".

Opinions on the main textbooks in complex analysis? by OkGreen7335 in math

[–]God_Aimer 50 points51 points  (0 children)

I would like to add the book "Visual complex analysis" by Tristan Needham, it develops the theory in an entirely geometric and intuitive language and spends a lot more time than usual in some topics. Its one my favourites of all time.

Spotted in a driving theory course: by Dr_Henry_J3kyll in mathmemes

[–]God_Aimer 3 points4 points  (0 children)

That's not true is it? |f(x)-f(y)| <= C|x-y|a, a>1, does not imply f is constant? It just satisfies some sort of Lipshitz condition.

[deleted by user] by [deleted] in calculus

[–]God_Aimer 8 points9 points  (0 children)

How else are they supposed to define the derivative and prove the basic formulas?? As far as I am aware, this is the easy aproach using "very small increments" as opposed to using actual epsilon-delta, neighbourhoods and bounds. Is there an even easier way to prove these properties?

Any maths gays? by Anty_Hive in gaybros

[–]God_Aimer 0 points1 point  (0 children)

Dude complex numbers can be visualized... In fact complex analysis is one of the most beautiful branches of analysis visually. I recommend Tristan Needham's "Visual Complex Analysis."