... Wick rotation . A Wick rotation is said conformal if there is also a positive horizontal rescaling function a such that , for every yЄ M , g \ < x ( y ) > + = a ( y ) h \ < x ( y ) > + . In fact , all metrics g , h as above are ...

... Wick rotation, the rotation to the imaginary k0 axis can be done in all Feynman integrals, because the integrand does k0 plane Figure 9.4 Wick rotation of contour to imaginary axis. The contour never crosses the poles of the Feynman ...

... Wick rotation in perturbation theory In the example of Fig . 9.1 , we evaluated the Feynman integral for spacelike values of its single external momentum , and then analytically continued to arbitrary complex momenta . This , in fact ...

... Wick rotation The first of these problems is handled by recalling the Wick rotation into Euclidean space that was used to define the functional integral . This rotation determined the sign of the iɛ in the free propagator . The Wick ...

... Wick rotation can be performed without any difficulty , in spite of the fact that the classical action in Euclidean space does not seem to be bounded from below ! 3. THE WICK ROTATION Let us concentrate a bit more on this Wick rotation ...

... Wick rotation is commonly considered only as a useful computational trick. However, as suggested by Hartle and Hawking already in early eighties, Wick rotation may gain physical meaning at the Planck epoch. While such possibility is ...

... αβγδ 75 W Y = -VÈYEYEYÊ CHUPO WiαBYS iЄE where € 1234 εμυρσ These definitions also imply that y formula :一尴. 13.3 Wick Rotation and Fermionic Functional Calculus 417 13.3 Wick Rotation and Fermionic Functional Calculus.

... Wick rotation in (2.135), t → -iτ (mapping time-like links into space-like links). After this Wick rotation into the Euclidean regime, the action Sdiscrete (also called the 'Regge action') is given by the expression Sdiscrete , (T) ...

... Wick rotation . At least in perturbation theory , one can prove that the conditions required to allow us to perform a Wick rotation are fulfilled . We notice that the Euclidean Feynman propagator obtained by the Wick rotation 1 1 q2 ...

... Wick rotation as shown in Fig. 3.5. Figure 3.5: The poles for n2 > 0. Only for |n|—¥0, but n2 > 0, we expect the possibility of a Wick rotation. However, for the light-cone gauge (with n2 = 0 entailing that n° ^ 0 and |n|^0) no Wick ...