That weird force pushing the universe apart? It might just be 'hair' growing off of black holes. No, seriously.
March 27, 2026
Original Paper
An effective cosmological constant as black hole primary hair
arXiv · 2603.25598
The Takeaway
For decades, the "no-hair theorem" suggested black holes were simple objects described only by mass, spin, and charge. This study suggests they could possess extra properties that naturally generate the cosmological constant—the energy driving the expansion of the universe—meaning the fate of the cosmos and the existence of black holes are deeply linked.
From the abstract
We study Generalized Proca theories inspired by the recent regularised Proca theory of four-dimensional Gauss-Bonnet gravity. By abandoning the rigid constraints typically imposed by specific regularization schemes, we treat the coefficients of the terms in the action as free parameters. This approach uncovers a broader solution space that admits static and spherically symmetric black hole solutions characterized by primary hair, where, surprisingly, the cosmological constant arises naturally as