• Seminar on Microlocal Analysis and Applications

    Zeroth order pseudodifferential operators on torus are studied as microlocal model of internal waves. These operators can have embedded eigenvalues. After 0th order analytic perturbations, the embedded eigenvalues become resonances and we prove a series expansion of the resonances. As results of the expansion, we obtain the Fermi golden rule for 0th order operators and we answer the question about the generic absence of embedded eigenvalues of 0th order operators asked by Colin de Verdiere.

  • Join us tonight for Tsinghua 2022 Gala Night

    Laughter, reunion with old friends, performances, warm vibes....That’s what the end of 2021 is for!

  • Ranging method of celestial bodies

    For more than 2000 years, every leap in human understanding of the universe and the laws of the universe depends on a better measurement of the distance of more distant celestial bodies. This lecture will review the human method of ranging celestial bodies for 2000 years, and take you from the Earth Moon system to the era of galactic cosmology.

  • Search for the century: the origin of neutrino mass

    The standard model of particle physics is a comprehensive theory to describe the basic laws of the micro world, and the non-zero mass of neutrinos is the only experimental phenomenon beyond the standard model. Clarifying the mass origin of neutrinos is a major problem to be solved in contemporary physics. With the theme of neutrino mass, the lecture reviewed the hypothesis and discovery of neut...

  • From Newton's apple to Einstein's black hole -- an introduction to general relativity

    From Newton's law of universal gravitation to Einstein's general theory of relativity is a qualitative leap in human understanding of the essence of gravitation. Over the past 100 years, various experimental observations, recent direct observations of gravitational waves and photos of black holes have verified the general theory of relativity, but the essence of gravity is still a major topic o...

  • From the evolution of the universe to the basic laws of Physics

    Since the beginning of civilization, human beings have been asking about the origin of the universe and the essence of all things. However, these questions can be answered quantitatively and accurately only through modern mathematics and physics. The modern cosmology established on this basis has not only opened the long history of the big bang for more than 10 billion years, but also brought n...