It took twenty years to demonstrate the existence ofand about forty for that at . How long does it take to demonstrate the existence of particles in or on the contrary to show their absence?
Recall that the neutrino was postulated byto maintain the law of conservation of energy in some nuclear decays that seem to violate it. But in doing so it must be admitted that the energy that seems to be lost is actually carried by a massless particle, which has no electrical charge and interacts with matter of such low energy that it can cross 300 Earths. no offense. We now know that there are three types of neutrinos and that they have masses, albeit very small ones.
Dark matter particles are just like ghosts, but paradoxically we must account for them for the existence ofand structures that unite them in the form of clusters containing from a few hundred to a few thousand galaxies are very nearly. This is under the effect of their field of that ordinary matter collapses faster than it should have on its own. We know for a variety of reasons that these dark matter particles are not the same as what we know on Earth and that they are mostly produced by collisions with at the LHC, although they are tracked there.
However, although dark matter is one of the pillars ofit does not exist and the observations it reports can also be explained by changing the celestial mechanics . It is a wonder now if the first discoveries of galaxies that seem very old in James-Webb, because it was observed more than 13 billion years ago, is not accurate .
For 13.8 billion years, the Universe has continued to evolve. Contrary to what our eyes tell us when we contemplate the sky, its composition is far from static. Physicists have observations of different ages of the Universe and make simulations in which they repeat its formation and its evolution. It appears that dark matter has played a major role since the beginning of the Universe until the formation of the massive structures observed today. © CEA Research
A new surprise in this regard may be about to endin an article published in by an international team of researchers led by members of Nagoya University in Japan. It mentions some results obtained by the Japanese Subaru telescope, in Hawaii, within the framework of the research campaign of (HSC), together with other observations obtained at in’ in the form of his famous map of the oldest light of can be observed, which was released about 380,000 after the in several thousand years.
Dark matter distorts the images of galaxies
Let’s also remember whatand the analyzes that he and his colleagues plan to make of this radiation in search of fundamental keys for and theoretical physics: The effect of makes it possible to reconstruct the integrated gravitational potential of the surface at the end until today. This is an interesting probe into the structures of the Universe. Therefore, if we succeed in this reconstruction, Planck will be an autonomous experiment sensitive to the entire evolution of the Universe, from the first universe at the time of the last dispersion to us. “.
The surface of the final dispersion is an imaginary globe that surrounds any observercan be observed and shows him the regions where the fossil radiation when the visible Universe became transparent because its density became so low that photons at that time could travel without colliding with charged particles that would scatter them over great distances.
The induced gravitational lens effect, in this case the so-called weak or even gravitational shear, is an effect of the deflection of light rays in a gravitational field that leads to the deformation of the initial image of a galaxy by a large mass interspersed between these galaxies. and an observer. We can infer from the deformation the mass of the body that produced it, so measuring the effects of gravitational lensing makes it possible to probe mass distributions in the visible cosmos, including the masses of dark matter. which itself does not shine.
In a vacuum, light usually travels in a straight line. But in a space deformed by a large celestial body, such as a galaxy, this trajectory deviates! Therefore, the light source located behind the galaxy has an apparent position different from its real position: this is the phenomenon of gravitational mirage. This video comes from the web documentary ” The Odyssey of Light (http://www.odysseedelalumiere.fr/comp…) and integrated into the web documentary ” Ride the Dark Matter (lamatierenoire.fr). © CEA-Animea
This effect has been used to estimate the presence and distribution of dark matter changes up to about 8 to 10 billion years ago. As Laurence Perotto also explained to us, the weak gravitational lensing effects produced byand foreground galaxies in the final scattering surface contaminates the study of fossil radiation and it is necessary to somehow remove this noise from the signal to return to the primitive state of fossil radiation. This makes it possible to trace the myth in particular primitives in the polarization of fossil radiation. Emphasizing these methods will convincingly demonstrate the existence of a violent inflationary phase of the expansion of space during the Big Bang.
Clusters of dark matter that have formed since the Big Bang
But, as the cosmologist said in the excerpt from his file that we provided, the measurement of the weak gravitational lensing effect could theoretically inform us about the presence and the variable nature over time and space of the dark matter from the appearance of the first galaxies to the present using fossil radiation.
The Japanese-led team was able to make precisely such observations beyond 8 billion years by measuring the effects of the galaxies seen by the HSC on Planck’s measurements of the background radiation. We haven’t been able to continue before because the galaxies, whose images are distorted by gravity, are too faint to make valid measurements.
But now researchers can go back about 12 billion years to the visible universe.
Remarkably, although still to be confirmed, the size characteristics of dark matter concentrations between 8 and 12 billion years ago do not seem to follow the predictions ofthe dark matter density fluctuations during this period appear to be weaker than expected.
one of the authors of the discovery and Professor ofInstitute for Cosmic Ray Research from the University of Tokyo, does not hesitate to explain: ” Our conclusion is still uncertain. But if true, that would suggest the whole model is flawed as you go back in time. This is interesting because if the result holds after the uncertainties are reduced, it may suggest an improvement in the model that can provide the nature of dark matter itself. »
With this goal in mind, cosmologists still need to addand accuracy of available data, which they will soon be able to do with the commissioning of the Vera C. Rubin Observatory, formerly known as .