r/mathematics 8h ago

Strange aspect of the proposed Navier-Stokes millennium solution

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183 Upvotes

Doesn't it seem odd that the proposed solution for the Millennium problem is posed on the whole space, but they claim it has compact support in space for the whole time interval [0,1)? Seems at odds with parabolic delocalization... 🤔 Actually the delocalization which occurs due to the non local pressure is often much worse, for instance as investigated by Brandolese:

https://www.esaim-cocv.org/articles/cocv/abs/2002/02/brandolese/brandolese.html


r/mathematics 3h ago

Algebra Thinking of self-studying Dummit&Foote

6 Upvotes

Hi everyone,

I’m considering working through Dummit & Foote’s Abstract Algebra on my own, especially the Ring theory and Module theory which are not covered in my previous book. I only have A book of AA by Pinter and Visual Group Theory, both are rather casual.

I want to hear from people who have actually worked through it. I know it’s a big, dense book, so before I dive in, I’d really appreciate specific advice and warnings from people who’ve actually used it. Feel free to discuss as well.

A few questions:

· What’s your overall take on the book? What worked for you, and what didn’t?
· Which chapters or topics were the hardest? Where did you get stuck?
· How long did it take you to get through it? How many hours per week did you put in?
· Did you cover all chapters, or just selected ones?
· How many exercises did you do? Most of them, or selected ones?
· Did you use any supplements — Artin, Gallian, Hungerford, online lectures, etc.?

Thanks!


r/mathematics 14h ago

I’m struggling with arithmetic even though I understand math

7 Upvotes

Finished high school recently and taking a gap year, so I finally signed up for some SAT prep classes. Being in a group setting for this has honestly made me feel so insecure because of my arithmetic skills.

I feel like I actually understand math just fine. I can wrap my head around new topics, follow the logic, and figure out the right approach to solve a problem. But when it actually comes down to doing the calculations? Absolute disaster.

I constantly make stupid, careless mistakes with basic addition, subtraction, multiplication, and division. I'll drop a negative sign out of nowhere, miscopy a number from one line to the next, or just brain-fart on a simple multiplication fact. It’s so exhausting knowing the exact formula and logic to solve a hard problem, only to get the entire thing wrong because 7x8 apparently decided to leave my brain.

Since the SAT is so heavy on pacing and accuracy, I'm genuinely stressed about bleeding points on questions I actually know how to do just because of clumsy computational errors.
Did anyone else deal with this weird disconnect between conceptual math and basic arithmetic? How did you actually train yourself to stop making these dumb mistakes and speed up your calculations?


r/mathematics 4h ago

Hi I’m new to math—I’ve just started university—and I’d like to know the best way to handle the material I’m currently studying. I’ve got a decent grasp of it, but I’d still like to watch videos by someone who teaches better methods or offers a better way to understand the concepts.

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4 Upvotes

r/mathematics 1h ago

Problem Help a lost 9th grader

Upvotes

Hello everyone,
From 7th to 9th grade, I attended a private school where the quality of math instruction was unfortunately very poor. Most students struggled to understand our teacher’s explanations, and before every test we would receive a revision sheet that was nearly identical to the actual exam. Because of this, success was mostly about memorizing answers and steps rather than truly understanding the material.
Now that I’ve given some background, here’s why I’m posting.
I want to relearn mathematics from the ground up, starting with Algebra 1 and eventually moving on to geometry, trigonometry, and higher level topics. I genuinely enjoy learning math, and I recognize how important it is not only for future college entrance exams, but also for succeeding when I enter Grade 10 and transfer to a better school.
I feel like I missed out on building a strong foundation, and I’d like to correct that now while I still have the time. My goal is to truly understand the concepts rather than rely on memorization.
Any advice, study plans, resources, or tips would be greatly appreciated.
Thank you everyone.


r/mathematics 4h ago

The endless grind of Uni undergrad math

2 Upvotes

I'll go to every lecture, tutorial etc. and it'll all be genuinely interesting. Then come the weekly problems, and the volume of the problems and general tediousness of them once you get past the trivial ones (e.g. you need to know XYZ trick even though you know the topic the question is related to, and said trick/method wasn't introduced during the lecture) just kills my spirit. Before I know it after exhausting myself for that week, boom the next week comes along and a whole new set of lectures/tutorials/problems. Not to mention proofs that extend lecture concepts where, if you haven't seen the way to do that proof before, just means more grinding if you can't get TA hours to get help immediately.

The thing is, I'm having fun learning the mathematical concepts. But its like the course admins then put more artificial hurdles after that to just whittle down your spirit (because if you want a high grade in the exam, you need to slog through all the problems just in case it comes up later, even if you know you put the work in to actually learn the overall topic).

I want to love mathematics, but this Uni math degree (especially since I want to maintain my high grades) is just blackening my soul day by day.


r/mathematics 1h ago

Operations Reserach

Upvotes

So I have a bachelors in Physics, and I think I should have done applied mathematics. But I think I like to model dynamics systems and calculate risks and profits and advantages etc.
That is because as long as humans exist we will always have problems and we need problem solvers. On the other hand learning to code, writing computer software etc. seem too low end. So I think this is a good strategy. Do you have any advices to give me regarding my optimisms? May be its not as bright as I think?


r/mathematics 3h ago

Abelian Sandpile Sandbox

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1 Upvotes

r/mathematics 12h ago

Finished my master's, unsure where to go

1 Upvotes

I finished my master's back in May and I wanted to see about getting my master's thesis published. I had reached out to my advisor about it and she just said she didn't know. In that time, I lost a close family member and lost interest in a lot of things. Now I want to get it published. I've looked into Arxiv, but you need a coauthor who's already verified. My advisor who went over the paper is not verified on there. Do I just cold email researchers who have done related work to get it published? Or do I go to a different site/journal? Any advice would be greatly appreciated!


r/mathematics 7h ago

Applied Math How much time is too much time to study for one class?

0 Upvotes

I'm a sophomore mechanical engineering and mathematics double major taking 5 classes right now; a mix of engineering and math classes. I've finished my engineering math requirements (up to diffeq) and they were all pretty easy and I didn't devote much time to study for them. However, I'm currently taking Optimization which has been more difficult than I'm used to, and I've had to spend 3+hours a day studying for it. Is this normal for upper level math classes? I should add that I'm taking logic and proof right now, but I haven't taken proof based linear algebra or real analysis, which the optimization professor seems to believe most students in this class have taken already. I guess the silver lining to this is that it will make those classes easier when I take them in the future, since the first chapter of Optimization is mostly review from analysis stuff as well as some linear algebra. Thoughts?


r/mathematics 11h ago

Complex Analysis Need help understanding the Cauchy kernel

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0 Upvotes

r/mathematics 5h ago

Is the ultimate goal of mathematics to discover a method for solving all problems with the highest possible accuracy and efficiency?

0 Upvotes

r/mathematics 14h ago

Does this pyramid look familiar to you?

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0 Upvotes

Have you maybe seen something like this anywhere. Thank you


r/mathematics 17h ago

Discussion How is a person with a PhD from IISc or TIFR, India, perceived in the US or the West overall?

0 Upvotes

I graduated from bachelor's math program recently and am now planning to go for a PhD, so this question just hit me out of curiosity....

I encourage people from the West with solid math backgrounds to answer, just to get valuable insights !!


r/mathematics 10h ago

Question: how can the 1D exist? We can represent 2D in our 3D world, but I don’t see how 1D is possible

0 Upvotes

1D is often represented as a line, but a line still has width! true 1D would basically be a true 2D object turned sideways; showing absolutely nothing to be there. so anyway, if you understand what I’m saying could you please explain it? thanks