Effective Field Theories, Gravity and Cosmology

Session

Cosmology

25 Apr 2025, 09:00

Building 3, 2A-223 (国科大杭州高等研究院 Hangzhou Institute for Advanced Study (UCAS))

Conveners

Cosmology

• Hong-Wei Yu

Cosmology

• Kohei Kamada (HIAS)

5. Cosmological collider from particle physics viewpoint

Prof. Masahide Yamaguchi (IBS, Korea)

25/04/2025, 09:00

The Higgs boson was discovered in the LHC experiment, but given the current lack of physics beyond the Standard Model of particle physics, such as supersymmetry, the importance of the universe as a means of exploring more fundamental laws of physics at high energies is expected to increase. In more fundamental theories beyond the Standard Model, it is believed that many new particles exist in...

26. Progress of higher derivative scalar-tensor theory: parity violation and multi-scalar extensions

Prof. Xian Gao (Sun Yat-sen U)

25/04/2025, 09:30

Scalar-tensor theory not only serves as one of the most important tools for constructing models in cosmology and gravitational wave research but also offers a broad playground for exploring modified gravity. In this talk, I will first review the development of scalar-tensor theory over the past two decades. In particular, I will present our efforts to utilize spatially covariant gravity as an...

34. Primordial Black Hole and non-Gaussianity

Prof. Shi Pi (ITP CAS)

25/04/2025, 11:00

I will briefly review the recent progress in the non-Gaussian effect on the primordial black hole formation and the induced GWs. The most promising mechanism of generating PBHs is by the enhancement of the primordial curvature perturbation, which is usually accompanied by the enhancement of non-Gaussianity that crucially changes the abundance of PBHs. I will discuss how non-Gaussianity is...

12. Thermal production of gravitational waves in the early universe

Xun-Jie XU (IHEP, China)

25/04/2025, 11:30

We investigate a novel gravitational wave (GW) production mechanism from gravitons generated during the pre-thermal phase of cosmic reheating, where the energy density is dominated by non-thermalized inflaton decay products, dubbed reheatons. We consider multiple production channels, including: i) pure inflaton-inflaton annihilation, ii) graviton Bremsstrahlung from inflaton decay, iii)...