From Semiconductors to Quantum Gravity: to Centenary of Matvei Bronstein

Investigation of the many-body condensed-matter systems allows us to connect the microscopic physics at the atomic energy scale and the macroscopic physics emerging in the low-energy corner. It gives some hints on the mechanisms of the formation of the physical laws which our Universe obeys. The paper is devoted to the centenary of Matvei Petrovich Bronstein. 1 Ether of 21-st century Each epoch in the history of physics has its own specific ether. M. Bronstein [1] The ether of the 21-st century is the quantum vacuum. The quantum ether is a new form of matter. This substance has a very peculiar properties strikingly different from the other forms of matter (solids, liquids, gases, plasmas, Bose condensates, radiation, etc.) and from all the old ethers. The new ether has equation of state p = −ǫ; it is Lorentz invariant; and as