Let Df denote the derivative of a function f(x) and bigtriangledownf=f(x)−f(x−1) be the discrete derivative. Using the Taylor series expansion for f(x−1), we easily get bigtriangledown=1−e−D or, by taking the inverses,
frac1bigtriangledown=frac11−e−D=frac1DcdotfracD1−e−D=frac1D+frac12+suminftyk=1B2kfracD2k−1(2k)!,
where B2k are Bernoulli numbers.
(Edit: I corrected the signs to adhere to the most common conventions.)
Here, (1/D)g is the opposite to the derivative, i.e. the integral; adding the limits this becomes a definite integral intn0g(x)dx. And (1/bigtriangledown)g is the opposite to the discrete derivative, i.e. the sum sumnx=1g(x). So the above formula, known as Euler-Maclaurin formula, allows one, sometimes, to compute the discrete sum by using the definite integral and some error terms.
Usually, there is a nontrivial remainder in this formula. For example, for g(x)=1/x, the remainder is Euler's constant gammasimeq0.57. Estimating the remainder and analyzing the convergence of the power series is a long story, which is explained for example in the nice book "Concrete Mathematics" by Graham-Knuth-Patashnik. But the power series becomes finite with zero remainder if g(x) is a polynomial. OK, so far I am just reminding elementary combinatorics.
Now, for my question. In the (Hirzebruch/Grothendieck)-Riemann-Roch formula one of the main ingredients is the Todd class which is defined as the product, going over Chern roots alpha, of the expression fracalpha1−e−alpha. This looks so similar to the above, and so suggestive (especially because in the Hirzebruch's version
chi(X,F)=h0(F)−h1(F)+dots=intXch(F)Td(TX)
there is also an "integral", at least in the notation) that it makes me wonder: is there a connection?
The obvious case to try (which I did) is the case when X=mathbbPn and F=mathcalO(d). But the usual proof in that case is a residue computation which, to my eye, does not look anything like Euler-Maclaurin formula.
But is there really a connection?
An edit after many answers: Although the connection with Khovanskii-Pukhlikov's paper and the consequent work, pointed out by Dmitri and others, is undeniable, it is still not obvious to me how the usual Riemann-Roch for X=mathbbPn and F=mathcalO(d) follows from them. It appears that one has to prove the following nontrivial
Identity: The coefficient of xn in Td(x)n+1edx equals
frac1n!Td(partial/partialh0)dotsTd(partial/partialhn)(d+h0+dots+hn)n|h0=dotshn=0
A complete answer to my question would include a proof of this identity or a reference to where this is shown. (I did not find it in the cited papers.) I removed the acceptance to encourage a more complete explanation.
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