李沃龍Lee, Wo-Lung何依黛Ho, I-Tai2025-12-092025-07-172025https://etds.lib.ntnu.edu.tw/thesis/detail/3c1cf30e675db2587c8fe708723807f9/http://rportal.lib.ntnu.edu.tw/handle/20.500.12235/125571noneGravitational waves offer a powerful window into the early universe. In this work, we inves- tigate the Running Vacuum Model (RVM), which features a time-dependent vacuum energy density that allows for a smooth transition from the inflationary phase to the radiation- dominated era. Within this framework, we focus on the inhomogeneous gravitational wave mode equation, treating it as a backreaction problem. By analyzing the resulting spectrum, we find that the amplitude of gravitational waves in the lower frequency range (105 to 107Hz) is suppressed compared to models with a discontinuous transition or without backreaction. This highlights the significant impact of smooth cosmic dynamics and particle production on the primordial gravitational wave background.noneEarly universeGravitational wavesRunning vacuum model學術論文