The Effect Of Dark Matter On The Braking Index And Surface Temperature Of Neutron Stars

The observation results in spiral galaxy show that except for the baryon matter,there is some other matter which can not observe directly and we call them dark matter.The dark matter disperses in the cosmic space and it interact with stellar through gravitation.Via the observation results we know that the cosmic matter is constitute of 68.3%dark energy?26.8%dark matter and 4.9%baryon matter.The neutron star was born in the supernova explosion which is the last period of the massive stellar's evolution.High density?short period and the strong magnetic field are the remarkable characters of the neutron star.The neutron star rotates with high speed in cosmic space,the cosmic medium will impact on its rotate speed via gravitation,which makes the neutron star slow down and we call it dynamic friction.It may be a new brake mechanism.Take the influence of dark matter's dynamic friction into account,we calculate the the neutron star's brake index.We combine three mech-anisms(magnetic dipole.gravitational radiation and dynamic friction)and analyze the region(0<n<1?1<n<3.3<n)of brake index which can explain the nine sources' brake index,then we give three different forms of brake index.As the central gravitational source,the accreted dark matter will annihilation in the neutron star and release energy which supports neutron star a new heating mechanism.We draw a conclusion that with the low dark matter density,there is the orbital constraint accreting model,the spherical accreting model exists in the high density surroundings.We comparing two different accretion ways and find that spherical accreting model can support a effective heating source which can explain the high temperature radiation from the old neutron star.This thesis composed of four different parts,in the first chapter we introduce the background knowledge of neutron star and dark matter;In the second chapter we discuss the neutron star's brake index in dynamics;The third chapter we focus on the release energy which produced from the dark matter's annihilation and comparing its effect to the neutron's surface temperature via two different accretion ways.In the last chapter,we summarize the paper and discuss the matters which we may encounter with in the future work.