2020/04/04 by Taichiro Kugo, Kugo, Taichiro
Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Gravitation Theories #Earth Systems and Cosmic Evolution #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.2004.01868
openalex publication_date 2020/04/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A scenario based on the scale invariance for explaining the vanishing\ncosmological constant (CC) is discussed. I begin with a notice on the\nmiraculous fact of the CC problem that the vacuum energies totally vanish at\neach step of hierarchical and successive spontaneous symmetry breakings. I then\nargue that the classical scale invariance is a necessary condition for the\ncalculability of the vacuum energy.\n Next, I discuss how sufficient the scale invariance is for solving the CC\nproblem. First in the framework of classical field theory, the scale invariance\nis shown to give a natural mechanism for realizing the miracle of vanishing\nvacuum energies at every step of spontaneous symmetry breakings. Then adopting\nEnglert-Truffin-Gastmans' prescription to maintain the scale invariance in\nquantum field theory, I point out that the quantum scale invariance alone is\nnot yet sufficient to avoid the superfine tuning of coupling constants for\nrealizing vanishingly small cosmological constant, whereas the hierarchy\nproblem may be solved. Another symmetry or a mechanism is still necessary which\nprotects the flat direction of the potential against the radiative corrections.\n