update

 a single idea which is -"spacetime get permanently deformed after gaining a critical threshold of stress,curvature or pressure like plastic do".  --"dark matter might be the left over permanent curved spacetime which are still gravitationally active present now like a fossil in the vacuum of past high energetical astrophysical event such as neutron star collapse, stellar collapse, supernovae explosion, blackholes collison etc . Moreover u can say any such events which leads the spacetime to gain a critical threshold by after that the spacetime get permanently curved even though the source of the curvature or gravity (ordinary matter) vanished from that area where the physical event happend. any such high energy astrophysical event may be the reason of that physical phenomenon because our core idea is that any event which can be the reason of leading the spacetime into a critical threshold can get generate a permanence curvature in the spacetime which are gravitationally active. there size might be small and bigger depends on how the event engaged with the spacetime and lead the spacetime to be permanently curved . so by far we discussed about the core mechanism of our goal and now we will try to solve the mystery of dark matter by this core idea of ours. we say that the curvature might be bigger or smaller like every event may not produce same permanency size or curvature in the spacetime. less energetic but still the even which leads the spacetime to a critical threshold may be make a smaller curved zone than the bigger or higher energetic astrophysical event.