13.4.11 |
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The contour of integration starts and terminates at a point
on the real axis between
and . It encircles and once in the positive sense,
and then once in the negative sense. See Figure 13.4.1. The fractional
powers are continuous and assume their principal values at .
Similar conventions also apply to the remaining integrals in this subsection.
13.4.12 |
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, . |
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At the point where the contour crosses the interval , and
the function assume their principal values; compare
§§15.1 and 15.2(i). A special case is
13.4.13 |
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13.4.14 |
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, . |
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The contour cuts the real axis between and . At this
point the fractional powers are determined by
and .