Physics far beyond

I wrote a  blog  about dark matter that accounts the most of mass of the universe. XENONnT is the latest dark matter detector generation located at the Gran Sasso International Laboratory in Italy. It contains 5.9 tons of liquid xenon waiting  for dark matter particles crashing into xenon atoms’ nuclei, causing them to recoil and emit electons to be detected.  In 2022 July published analysis of 97 days data shows no signs of dark matter particle collisions. This feels a bit disapointment as in 2020, the precessor detector XENON1T found excess of  ricocheting electrons. The cause of the surplus was explained by hypothetical lightweight particles that may originate from the sun called solar axions.  But the excess wasn’t large enough to be convincing, so more data were needed. No reason found for the previous excess but it may have been a statistical fluke.  Similarly, the latest experiments of new generation LZ detector (2022 July) found no dark matter. The detector is 1.5 km undergroun

The previous post discussed of dark matter that appears to have gravity effect to hold galaxy clusters together. However, in the larger scale the universe is expanding and galaxy clusters are moving away from us. In 1998, the red shift measurement from the distant galaxies revealed that the rate of expansion is accelerating. According to the general relativity, the matter content of the universe curves all spacetime causing  a global gravitational effect, which would decelerate the expansion. Thus something must counteract and win  the gravitation.   Currently,  dark energy has been the most accepted premise to account for the accelerated expansion and is a part of the standard cosmological lamda-CDM model.  Cosmologists' well-tested standard model assumes that 68% of the content of the universe is dark energy. However, the origin and composition of dark energy is one of the biggest mysteries. The simplest explanation for the dark energy is the cosmological constant,  representing