Exploring phantom dark energy and Chandrasekhar limit through a modified uncertainty principle

This study emphasizes that the tendency of observational dark energy to the phantom phase requires an extended uncertainty principle (EUP) parameter with the opposite sign. On the other hand, several studies have shown that the generalized uncertainty principle (GUP) eliminates the Chandrasekhar limit for stars, but this critical limit can be restored using a GUP parameter with the opposite sign. However, it is challenging to change the sign of the GUP and EUP parameters without a physical justification. In this study, it is shown that including the cosmological constant in a modified uncertainty principle (MUP) allows the sign change in both the GUP and EUP to be handled in a unified framework. The main advantage of the MUP is that the sign change of the cosmological constant is both allowed and geometrically meaningful. To achieve this, we first derive the modified equation of state, entropy, and chemical potential from the EUP framework. Fitting the modified equations to phantom dark energy observations and assuming the correct sign for the cosmological constant leads to appropriate corrections to the thermodynamic quantities and has interesting physical consequences. Also, based on the proposed method, we show that the Chandrasekhar mass limit for stars provides an upper limit [Formula: see text] for the cosmological constant, which aligns with the observational range of [Formula: see text].