# Reference request: parabolic PDE

I want to learn about parabolic PDE and it seems to me that there is no established reference as far as where one should look if one wants to learn the subject from basics.

I think I have a firm grip on elliptic PDE after going through the first part of Gilbarg and Trudinger + some Monge-Ampere stuff. But that concludes my PDE background at this moment.

Can someone provide me with a good textbook for parabolic PDE? Any chunk of information will be appreciated.

EDIT: I would like to learn about parabolic PDE arising in geometry, mostly the Kahler-Ricci flow and related questions. But since I am new to this approach perhaps a more broad introduction would be appropriate.

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Friedman's Partial Differential Equations of Parabolic Type may be a good choice. –  user23078 Oct 7 '12 at 10:47

If you are interested in sup-norm and Hölder estimates, then Lunardi's book is a good start:

http://www.amazon.com/Semigroups-Regularity-Parabolic-Differential-Applications/dp/3764351721/ref=la_B001K6J69O_1_1?ie=UTF8&qid=1349596684&sr=1-1

Otherwise you should specify what type of equation are you interested in.

ADDED: Afret the comment of @Liviu:

You should not omit Krylov's books from your list: the one on Hölder spaces and the one on $L^p$ spaces.

And of course there is Evans. An excellent introduction.

ADDED: After the clarification in the question: Topping's lecture notes (there is also a book version from the London Mathematical Society) are quite nice and readable.

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Here are some useful references. J.L. Lions, E. Magenes: Non homogeneous boundary value problems, vol.II Springer Verlag, 1972 and A. Friedman: Partial Differential Equations, Dover 2008, H. Brezis: Functional analysis, Sobolev Spaces, and Partail differential Equations, Springer Verlag 2011. Brezis' book would be the place to start. Lions and Magenes is the most sophisticated but it only deals with Hilbert spaces, i.e., $L^2$-based Sobolev spaces. –  Liviu Nicolaescu Oct 7 '12 at 12:45
Thanks for the suggestions. As it was rightfully asked, I edited my question to reflect my motivation of study. Perhaps this narrows a few things down. Does it? –  The Common Crane Oct 7 '12 at 20:53
Somebody knowledgeable recommended Lieberman's book because it is similarly written to Gilbarg & Trudinger. Is it worth it compared to other choices? –  The Common Crane Oct 10 '12 at 0:20

I have to kindly dissent from Deane Yang's recommendation of the books that I coauthored. The reason being that the question by The Common Crane is about basic references for parabolic PDE and he/she is interested in Kaehler--Ricci flow, where many cases can be reduced to a single complex Monge-Ampere equation, and hence the nature of techniques is quite different than that for Riemannian Ricci flow.

I would second user23078's recommendation of Avner Friedman's Partial Differential Equations of Parabolic Type (beautifully and carefully written), and Andras Batkai's recommendation of Nick Krylov's book Lectures on Elliptic and Parabolic Equations in Sobolev Spaces, AMS Graduate Studies in Mathematics Volume 96 [11-18-2013: this is a correction: earlier I quoted the wrong book [Hoelder spaces]] (my colleague Lei Ni will use this book next quarter for the second part of the graduate PDE course at UCSD). To the books mentioned in the above posts on elliptic and general PDE, I would add the book by Qing Han and Fanghua Lin titled Elliptic Partial Differential Equations (in my opinion, it is a really good book; I've been using it in the PDE graduate class this quarter).

For many aspects of Ricci flow, perhaps the same may be said for Kaehler--Ricci flow, one does not need to know much parabolic PDE per se (although knowing more always helps). A fair percentage of estimates in Ricci flow are what one could call Bochner formulas. In this sense, it may be helpful to see some classic examples. A few that come to mind (perhaps not representative), are:

(1) The Bochner formula for 1-forms on a closed Riemannian manifold, which shows that there are no harmonic 1-forms if $\operatorname{Ric}>0$.

(2) The Weyl estimate used in the Weyl embedding problem; see e.g. Nirenberg's paper.

(3) Lichnerowicz formula for estimating $\lambda_1$ when $\operatorname{Ric}$ is bounded from below by a positive constant.

(4) For modern geometric analysis, the works of S.T. Yau and his coauthors on the many applications of PDE (especially the maximum principle) to problems in geometry. For parabolic equations, his paper with Peter Li on differential Harnack estimates for heat-type equations is an absolute must read. Anecdotally, I was once in Nick Krylov's house in Minnesota and I wandered into his basement and I went into his study. There, sitting prominently on the center of his table, was Li and Yau's paper. I thus learned a trade secret.

(5) Regarding Kaehler--Ricci flow, I would look into the specific techniques and calculations that workers in the field use and perform. For some of the references they quote, they may just use the techniques; for other references that they quote, they may just use the results. It may be more efficient to focus on those aspects that are most pertinent to what you are studying.

The above comments only refer to a minuscule, albeit fundamental, part of the landscape.

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Ben, great advice! You should post more. –  Deane Yang Oct 14 '13 at 4:29

If it's the Ricci flow you're really interested in, I recommend checking out the books on the Ricci flow written by Bennett Chow and his co-authors.

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