2025/11/29 by C. Y. He, Chao Liu, He, Chihang +1
Physics and Astronomy · #Cosmology and Gravitation Theories #Black Holes and Theoretical Physics #Noncommutative and Quantum Gravity Theories
paper · pdf · doi:10.48550/arxiv.2512.00455
We provide a rigorous proof for the existence of homogeneous, isotropic and globally singularity-free cosmological solutions in Einstein-dilaton-Gauss-Bonnet (EdGB) gravity with exponential coupling. While numerical studies suggested such solutions exist, a formal proof remained elusive. By employing a novel ``power identity method'' and overcoming significant challenges posed by the strong nonlinearities of the exponential coupling, which are not present in the quadratic coupling analyzed in our companion paper \citehe2025proofssingularityfreesolutionsscalarization, we establish a FLRW solution valid for all time t∈(-∞,+∞), where the Hubble parameter remains positive and vanishes asymptotically, while the scalar field evolves monotonically. This result align with numerical simulations and offer a firm mathematical foundation for singularity-free cosmology in a string-inspired setting.