Name: Methods of mathematical physics
ISBN: 9780470179529

What Hacker News says

enriqutoJan 2023

The classical stuff is great:

* Geometry and the imagination by Hilbert and Cohn-Vossen

* Methods of mathematical physics by Courant and Hilbert

* A comprehensive introduction to differential geometry by Spivak (and its little brothers Calculus and Calculus on manifolds)

* Fourier Analysis by Körner

* Arnold's books on ODE, PDE and mathematical physics are breathtakingly beautiful.

* The shape of space by Weeks

* Solid Shape by Koenderink

* Analyse fonctionnelle by Brézis

* Tristan Needhams "visual" books about complex analysis and differential forms

* Information theory, inference, and learning algorithms by MacKay (great book about probability, plus you can download the .tex source and read the funny comments of the author)

And finally, a very old website which is full of mathematical jewels with an incredibly fresh and clear treatment: https://mathpages.com/ ...I'm in love with the tone of these articles, serious and playful at the same time.

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enriqutoJul 2020

The princeton companion is nice to have around, but you do not really read it end to end.

Spivak's calculus you bring to the beach and read it between swim and swim.

EDIT: Also, some books by Hilbert are breathtakingly beautiful: Geometry and the Imagination (just the chapter on synthetic differential geometry is worth more than 10 other great books), and the Methods of Mathematical Physics is also great. It begins by giving three proofs of cauchy-schwartz inequality, and then goes on to give several different definitions of the eigenvectors of a matrix. Both of those make great beach readings for this summer.

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oddthinkAug 2024

I always come back to Schutz's Geometrical Methods of Mathematical Physics as my reference for notation, but I agree. I came to this by way of General Relativity, so that colors my perceptions. The few treatments of GA that I've looked at (briefly) weren't very clear about the distinction between 1-forms and 1-vectors and seemed to assume Euclidean metric everywhere, so I left thinking that it seemed a little weird and not quite trusting it.

In any case, my experience is that the coordinate-free manipulations only go so far, but that you pretty quickly need to drop to some coordinates to actually get work done. d*F=J is nice and all, but it won't calculate your fields for you.

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hintymadJan 2023

For what level and in which area? Books like _Methods of mathematical physics_ can be both too hard and irrelevant to your needs. For starters,

To become a better problem solver with high-school level maths:

  - Polya's How to Solve It.
  - Books of your choice about math contests.
  - Concrete Maths. I understand that this book is taught in college, but it requires very little advanced maths, and its techniques are hugely useful for high school students too.

To hone my intuitions. I learned it the hard way that college maths were different from high school math: in high school, my teachers painstakingly drilled intuitions into us with very targeted explanations and tons of well designed exercises. In college, we won't get such luxury. So, it's really up to us to understand mathematical concepts intuitively before diving into technical details. For that matter, the following books helped me a lot:

  - The visual series. Visual Complex Analysis and Visual Group Theory, for instance
  - Pinter's A book of Abstract Algebra
  - Strichartz's The Way of Analysis
  - Linear Algebra Through Geometry by Wermer. The book offers a comprehensive geometric interpretation to linear algebra concepts. It's especially helpful for me to understand quadratic forms.

To understand Analysis better. This area is vast, so I'll skip recommendations of excellent text books:

   - _Counterexamples in Analysis_. Those counterexamples in Analysis play a huge role in helping me truly appreciate the intricacies of Analysis. Similarly, books like _Counterexamples in Probability and Real Analysis_ are of great help too.
   - The Way of Analysis by Robert S. Strichartz. This books is AMAZING for laymen like me. You'd want someone to *explain* how concepts emerge, and how intuitions evolve.

To become good at maths by doing maths, so the following books used to help me a lot:

  - Problems and Proofs in Real Analysis
  - Putnam and Beyond. I still suck at maths, but those well designed problems in Putnam really taught me how to seek insights in higher maths.
  - Piotr's Problems in Mathematical Analysis. But really, any problem books that challenge you will do. I'd recommend you find problem sets from the website of university courses. They cover essential techniques, and will not be as overwhelming as the books.

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mjreacherDec 2022

Dirac came from a later generation than Einstein. For example during Einstein's annus mirabilis (1905) I doubt very many physicists knew of tensor calculus considering it was only developed a decade beforehand. During that time the mathematics physicists learnt was very much the traditional topics of analysis: series expansions, special functions, integral equations, calculus of variations, quadratic forms and of course partial differential equations. Hilbert himself actually wrote a textbook with Richard Courant covering these topics: Methods of Mathematical Physics. As such I don't really think many physicists of Einstein's generation knew lots of mathematics simply because it wasn't taught at the time. In the decades since physicists gradually has generally become more "mathematised" so to speak. In Dirac's generation tensor calculus and group representation theory became important, than in general abstract algebra and functional analysis, then as differential geometry became more well developed that gets taught and closer to the modern day you can find top theoretical physics students learning all sorts of abstract mathematics like algebraic topology.

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jasomillNov 2021

While certainly not the usual approach, calculus in terms of infinitesimals has been placed of formal foundations[1]. To be fair to Courant, however, the approach to infinitesimals in nonstandard analysis is pretty far removed from the views of Leibniz, et al., and "mystical associations" is a fair, if not necessarily impartial, criticism of the latter.

IIRC, even Newton was at least a bit skeptical of the validity of his method of fluxions, even going so far as to formulate his Principia in terms of (nearly impenetrable IMO) arguments from classical geometry instead, and the non-rigorous application of related ideas led even the best mathematicians to questionable conclusions at times (e.g., Euler's argument that 1 + 2 + 4 + ⋯ = -1, which may or may not have influenced computer science in terms of two's complement arithmetic).

As for abstraction as a source of seemingly artificial difficulty in modern mathematics, from the introduction to Courant's Differential and Integral Calculus, the first edition of Introduction to Calculus and Analysis[2],

The presentation of analysis as a closed system of truths without reference to their origin and purpose has, it is true, an aesthetic charm and satisfies a deep philosophical need. But the attitude of those who consider analysis solely as an abstractly logical, introverted science is not only highly unsuitable for beginners but endangers the future of the subject; for to pursue mathematical analysis while at the same time turning one's back on its applications and on intuition is to condemn it to hopeless atrophy.

For similar arguments that over-reliance on formalism begins far earlier in the modern mathematical curriculum, see Feynman's New Textbooks for the "New" Mathematics [3], in which he discusses his frustrations as a working (theoretical!) physicist reviewing grade school textbooks.

As a partial counterpoint, I personally often have an easier time understanding the more abstract treatments. For example, I struggled with the traditional presentation of multivariable calculus in terms of "physically meaningful" differential operators until working through the first couple books of Spivak's Comprehensive Introduction to Differential Geometry after-hours, at which point everything sort of clicked. Had my intro (college) calculus course not coincidentally been taught by a differential geometer with a habit of presenting some of the basic ideas as asides, I may have never made it any further in the field (in terms of learning; I work in software, not maths).

Nevertheless, I'd never propose Bourbaki as a good model for elementary education!

Revised (Introduction to…) editions of Courant's calc textbooks are particularly noteworthy in this respect; to me, at least, they strike a very good balance between classical and modern formalisms, and between applications to pure and applied mathematics.

As for the application of "general abstract nonsense" to computer science and engineering, I have no doubt Courant would be pleased, with the applications if not in their presentation, as the interplay between pure mathematics and its applications was always an important subject to him (see also the introduction to his [and, nominally, Hilbert's] Methods of Mathematical Physics [4], the address he gave on variational methods in PDEs [5], often cited as a foundational work in finite element analysis, and, well, pretty much the entirety of What is Mathematics?[6]).

[1] https://en.wikipedia.org/wiki/Nonstandard_analysis

[2] https://onlinelibrary.wiley.com/doi/pdf/10.1002/978111803324...

[3] http://calteches.library.caltech.edu/2362/1/feynman.pdf

[4] https://onlinelibrary.wiley.com/doi/pdf/10.1002/978352761721...

[5] https://www.ams.org/journals/bull/1943-49-01/S0002-9904-1943...

[6] https://archive.org/details/WhatIsMathematics

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