The discovery of symmetry-protected states of matters in topological insulators and semimetals has attracted tremendous interest in a wide range of areas fromcondensed matter physics to materials science and high-energy physics. Byconsidering nonsymmorphic symmetries, we extend conventional TIs tononsymmorphic TIs, including hourglass fermions and topological Diracinsulators. After the discovery of Weyl and Dirac fermions in topologicalsemimetals, we find several distinct types of fermions excitations in solidstate systems of 230 space groups , such as spin-1 and spin-3/2 excitations，which have no high energy analogs. Exotic surface Fermi arcs and uniquemagneto-electric response are expected in these novel semimetal phases. Primordial non-Gaussianities record interactions of elds in the early universe, which can be viewed as collision events in a "Cosmological Collider" with huge energy. In this talk, I shall introduce the workings of the Cosmological Collider as an explorer of new physics at very high scales, and describe the Standard Model spectrum during in ation and its "background signals" in Cosmological Collider. The nontrivial quantum correction during in ation plays a crucial role in this process, which I shall describe in detail.
Dr.Wang got his PhD degree from IOP, CAS in Beijing in 2014. He was studying Density Functional Theory and Dynamic Mean-Field Theory in Prof. Z. Fang and Prof. X. Dai's group. They proposed several Dirac semimetals, which areverified by experimental groups worldwide. After the graduation from IOP, he went to Princeton University as a postdoctoral research associate, working with a theoretical physicist, Prof. B. Andrei Bernevig. Since then, he has achieved lots of progress in study of topological phases in solids of 230 space groupsand predicted some novel topological materials. So far, his publications include Nature, Science, Nature Physics, Nature materials, Science Advances, PRX, PRL, and PRB, etc. The total citation is about 4700 with h-index 22 from Google Scholar. His current interest is focused on topological quantum materials and their novel properties in experiments.