Viscous Coefficients of a Hot Pion Gas

<table>The contour <svg height="11.75" id="M28" style="vertical-align:-0.23206pt" version="1.1" viewbox="0 0 12.1125 11.75" width="12.1125" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,11.4)"><path d="M682 629q-1 -16 -1.5 -72t-2.5 -86l-31 -4q-5 92 -51 129t-139 37q-100 0 -177 -49t-116 -125t-39 -162q0 -122 66 -201t182 -79q83 0 137 42.5t112 128.5l26 -15q-12 -31 -42.5 -88t-45.5 -75q-139 -27 -199 -27q-148 0 -243 81.5t-95 226.5q0 173 129.5 274.5
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</svg> in the complex time plane used here for the real-time formulation.</table>

Advances in High Energy Physics

Viscous Coefficients of a Hot Pion Gas

Figure 1