Chinese scholars and overseas collaborators discovered the new nonlinear dynamics of primordial gravitational waves

The main method of exploring the origin of the universe is to search for time and space ripples from the creation period of the universe, that is, the original gravitational waves.
The magnitude of these time and space fluctuations is directly determined by the cosmic energy scale in the infant period
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Therefore, the ability to capture the original gravitational waves has become one of the key clues to whether humans can find high-energy new physics beyond the standard model of particle physics in the infant universe

Cai Yifu’s team introduced a heavy field with parametric resonance evolution behavior to make it nonlinearly couple with the original gravitational wave, thereby providing an energy source for the resonance gain of the original gravitational wave
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In addition, the slow-roll dynamics satisfied by the evolution of the inflationary background can make the heavy field and the traditional primordial matter disturbances hardly interfere with each other, so as to ensure that the inflation theory is in perfect harmony with the current cosmological observations

Exploring the vast and unknown universe, especially the issue of the "origin of the universe" has always been of great appeal to mankind
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With the advent of the age of gravitational wave astronomy, humans can not only "see" the universe through telescopes of electromagnetic signals, but also "listen" to the universe through gravitational wave telescopes

Figure 1 In the physical desert in the high-energy zone, there is a small piece of new physical oasis, which is amplified to the observable range by the original gravitational wave resonance gain mechanism, and can be detected and verified by the cosmic microwave background radiation telescope
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Background image source: European Space Agency/Planck Cooperation Group

Figure 2 The dynamics of parametric resonance and nonlinear gain of the original gravitational wave in a specific physical environment
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Left: The amplitude gain of the parametric resonance refield (black line) and the comparison with the traditional primordial matter disturbance (red line); Right: The theoretical prediction signal (black line, red line) given by the newly proposed primordial gravitational wave resonance generation mechanism (black line, red line) and Comparison of the detection capabilities of the international LiteBIRD space telescope (green line)