Gravitational interactions in very young high-density stellar clusters can to some degree change the angular momentum in the circumstellar discs surrounding initially the majority of stars .
However , for most stars the cluster environment alters the angular momentum only slightly .
For example , in simulations of the Orion Nebula cluster ( ONC ) encounters reduce the angular momentum of the discs on average at most by 3-5 % and in the higher density region of the Trapezium by 15-20 % - still a minor loss process .
However , in this paper it is demonstrated that the situation is very different if one considers high-mass stars ( M ^ { * } > 10 M _ { \sun } ) only .
Assuming an age of 2 Myr for the ONC , their discs have on average a 50-90 % lower angular momentum than primordially .
This enormous loss in angular momentum in the disc should result in an equivalent increase in accretion , implying that the cluster environment boosts accretion for high-mass stars , thus making them even more massive .