Fluid sphere: stability problem and dimensional constraint
  We study different dimensional fluids inspired by noncommutative geometry which admit conformal Killing vectors. The solutions of the Einstein field equations examined specifically for five different set of spacetime. We calculate the active gravitational mass and impose stability conditions of the fluid sphere. The analysis thus carried out immediately indicates that at $4$-dimension only one can get a stable configuration for any spherically symmetric stellar system and any other dimensions, lower or higher, becomes untenable as far as the stability of a system is concerned. 
Farook Rahaman, Anirudh Pradhan, Nasr Ahmed, Saibal Ray, Bijan Saha   and Mosiur Rahaman
gr-qc