What font is it that was used in this document?

Question

I was wondering if anyone knows the name of the font used in screenshot below? Thanks in advance!

Answer 1

This seems to be Palatino, with math from mathpazo. Just to point out: you can also use this font with the more recent (and actively maintained) bundle newpx, although the math font is slightly different (the greek letters differ a bit, for example).

\documentclass{article}
\usepackage{amsmath}
\usepackage{mathpazo}
\begin{document}
\setcounter{section}{3}
\setcounter{subsection}{2}
\subsection{The proof of the ``if''-part of Theorem 3.1}
Suppose that \(f\) satisfies multiplicative symmetries. Denote by \(\sigma(N)\) the sum of the positive divisors of \(N\). By Lemma 3.3, we have
\begin{align*}
    & \epsilon_N q^{\sigma(N)} \prod_{\substack{ad=N \\ 0\leq b<d}} \Bigl( f^{(as)} (\zeta_d^b q^{a/d}) - f^{(as)}(r) \Bigr) \\
    & = \prod_{\substack{ad=N \\ 0\leq b<d}} \biggl( 1 - \zeta_d^b q^{a/d} f^{(as)}(r) + \sum_{m=2}^\infty H_{m-1}^{(as)} \zeta_d^{bm} q^{am/d} \biggr)
\end{align*}
\end{document}

Answer 2

It's called Palatino.

I highly recommend to look at: How do I find out what fonts are used in a document/picture? which was suggested in this comment by David Carlisle, but the top answer to that question requires you to have a PDF file with the font in it.

Fortunately, even without the PDF file I was able to recognize this font because I have used it for almost all of my papers, for example here, and here and here.