# L_2-norm representation

Let $$f^{\alpha}_+(x)=\frac{1}{\Gamma(\alpha+1)}\sum_{k\ge 0}(-1)^k{\alpha+1 \choose k}(x-k)^{\alpha}_+,$$ where $\alpha > -\frac 12$. I am wondering if one can get nice representation of $L^2$-norm of the function $f^{\alpha}(x)$, namely $$\int_{-\infty}^{\infty}(f^{\alpha}_+(x))^2dx.$$

(Here $y^{\alpha}_+=\max(0, y)^{\alpha}$ is a one-sided power function).

Thank you.

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I fixed the Latex. –  Ulrich Pennig May 16 '12 at 17:19
Cross-posted to MSE: math.stackexchange.com/questions/145188/… –  Yemon Choi Jun 8 '12 at 21:19