The line-of-sight analysis of spatial distribution of galaxies in the
  COSMOS2015 catalogue
  New observations of high-redshift objects are crucial for the improvement of
the standard $\Lambda$CDM cosmological model and our understanding of the
Universe. One of the main directions of modern observational cosmology is the
analysis of the large-scale structure of Universe, in particular, in deep
fields. We study the large-scale structure of the Universe along the line of
sight using the latest version of the COSMOS2015 catalogue, which contains
518,404 high quality photometric redshifts of galaxies selected in the optical
range of the COSMOS field ($2\times 2$ deg$^2$), with depth up to the redshift
$z \sim 6$. We analyze large-scale fluctuations in the number of galaxies along
the line of sight and provide an estimate of the average linear sizes of the
self-correlating fluctuations (structures) in independent redshift bins of $
\Delta z = 0.1 $ along with the estimate of the standard deviation from
homogeneity (the observed cosmic variance). We suggest a new method of the
line-of-sight analysis based on previous works and formulate further prospects
of method development. For the case of the theoretical form of approximation of
homogeneity in the $\Lambda$CDM framework, the average standard deviation of
detected structures from homogeneity is $ \sigma_\text{mean}^{\Lambda
\text{CDM}} = 0.09 \pm 0.02 $, and the average characteristic size of
structures is $ R_\text{mean}^{\Lambda \text{CDM}} = 790 \pm 150 $ Mpc. For the
case of the empirical approximation of homogeneity, the average standard
deviation of detected structures from homogeneity is $
\sigma_\text{mean}^\text{empiric} = 0.08 \pm 0.01 $, and the average
characteristic size of structures is $ R_\text{mean}^\text{empiric} = 640 \pm
140 $ Mpc.
