Barashkov, Nikolay, and Petri Laarne. “Invariance of \(\phi^4\) Measure under Nonlinear Wave and Schrödinger Equations on the Plane”. Annales Fennici Mathematici 51, no. 2 (June 16, 2026): 449–504. Accessed October 11, 2026. https://afm.journal.fi/article/view/185670.