Critical scaling for spectral functions

Abstract:

We study real-time scalar    -theory in 2+1 dimensions near criticality. Specifically, we compute the single-particle spectral function and that of the  -channel four-point function in and outside the scaling regime. The computation is done with the spectral functional Callan-Symanzik equation, which exhibits manifest Lorentz invariance and preserves causality. We extract the scaling exponent   from the spectral function and compare our result with that from a Euclidean fixed point analysis.

K. Kockler, J. M. Pawlowski, J. Wessely, „Critical scaling for spectral functions“, 10. Juni 2025,
arXiv:2506.09142 (2025).

https://arxiv.org/abs/2506.09142

Related to Project A02