Experiment Neutrino-4 search for sterile neutrino and results of measurements.

The experiment Neutrino-4 had started in 2014 with a detector model and then was continued with a full-scale detector in 2016 - 2021. All steps of preparatory work on this experiment are presented. Here we present all results of the Neutrino-4 experiment with increased statistical accuracy provided to date. The results of the flux dependences of reactor antineutrinos and their spectra from distances to the center of the active zone of the SM-3 reactor (Dimitrovgrad, Russia) in the range of 6-12 meters are presented. Using all the data, we performed a model-independent analysis to determine the oscillation parameters $\Delta m_{14}^2$ and $\sin^22\theta_{14}$. The method of coherent addition of measurement results allows to directly demonstrate the oscillation effect. We present the analysis of possible systematic errors and the MC model of the experiment, which considers the possibility of the effect manifestation at the present precision level. As a result of the analysis, we can conclude that at currently available statistical accuracy we observe the oscillations at the $3.2\sigma$ level with parameters $\Delta m_{14}^2=(7.2\pm0.13_{st}\pm1.12_{sys})\text{eV}^2 = (7.2\pm1.13)\text{eV}^2$ and $\sin^22\theta_{14}= 0.26\pm0.08_{stat}(3.2\sigma)$. We plan to improve the currently working experimental setup and create a completely new setup in order to increase the accuracy of the experiment by 3 times. A brief analysis of the general experimental situation in the search for sterile neutrinos is presented.