9 papers
Topological obstructions to geometric positivity and negativity on Calabi-Yau manifolds
Ping Li
We study whether the topology underlying a Calabi-Yau manifold can support natural geometric positivity or negativity structures. In even complex dimension (assuming $b_…
Probing small-scale primordial power spectra with induced gravitational waves
Di Wu, Zhi-Chao Li, Peng-Yu Wu +2
Large-scale primordial perturbations have been well constrained by current cosmological observations, but the properties of small-scale perturbations remain elusive. This study foc…
Cosmological constraints on small-scale primordial non-Gaussianity
Jing-Zhi Zhou, Zhi-Chao Li, Di Wu
In contrast to the large-scale primordial power spectrum and primordial non-Gaussianity , which are strictly constrained, the small-scale $\mat…
Tensor induced gravitational waves
Fei-Yu Chen, Jing-Zhi Zhou, Di Wu +2
Primordial gravitational waves on small scales are not tightly constrained by current cosmological observations, which allows for the possibility of large amplitudes at small scale…
Can tensor-scalar induced GWs dominate PTA observations ?
Di Wu, Jing-Zhi Zhou, Yu-Ting Kuang +3
Observational constraints on small-scale primordial gravitational waves are considerably weaker than those on large scales. We focus on scenarios with significant primordial gravit…
Induced gravitational waves for arbitrary higher orders: vertex rules and loop diagrams in cosmological perturbation theory
Jing-Zhi Zhou, Yu-Ting Kuang, Di Wu +2
Gravitational waves induced by primordial perturbations serve as crucial probes for studying the early universe, providing a significant window into potential new physics during co…