Since the discovery of the first radio pulsar in 1967, the known population of neutron stars has grown steadily and there are now approximately 2000 objects identified out of the 10⁸ possible neutron stars in the Galaxy. Still, the major part of population remains terra incognita for modern astrophysics. The most appropriate method to uncover the whole picture is the population synthesis technique.

The basis of population synthesis is a commonly agreed upon evolutionary scenario for all types of objects that includes initial conditions. The result of the synthesis is a set of parameters — which allow us to reproduce the observed sample (i.e. such properties as period—period derivative distribution, pseudo radio luminosity at 1400 MHz and spatial distributions). This type of study requires the most reliable physical scenario. If the assumed model was too far from the real physical evolution, we might end with a set of parameters which do not reflect the properties of the real sample. From this point of view the population synthesis is like putting together parts of a great puzzle. Currently, the magnetic field decay law, the cooling of neutron stars and parameters at their formation remain unresolved.

Unfortunately, this method includes many coupled values, so it is possible to produce a good fit of the final distributions by changing two values simultaneously. Among the most important pairs are the parameters of magnetic field decay and initial period distribution, and birth kick velocity and the distribution of initial heights.

The best solution to uncoupling these values it is to step away from the population synthesis technique and look closely at the youngest pulsars. We can assume that they should not have evolved much and their modern state is not very different from the birth state.

My work will revisit the population synthesis technique based on youngest pulsars and then run the synthesis method to look on the whole picture.