So I thought it didn't matter which side of the equation the cosmological constant was one (did it emerge from geometry or the stress energy tensor). However, then I remembered the weak , strong, null, etc energy conditions. Now, if I presume the cosmological constant emerged from the stress energy tensor the this has a direct implications on these inequalities? Or does one say these inequalities are true up to a cosmological constant? What happens if these conditions are violated?

Will be grateful if anyone can shed some light?


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You are correct that if the cosmological constant is interpreted as being from the stress-energy tensor then it violates the strong energy condition. This is because the strong energy condition can be stated that the pressure plus density of a fluid must be greater than zero. While this holds for non-relativistic matter and radiation it is violated for a cosmological constant as the sum of the pressure and density is zero in that case. There are no adverse consequences to this violation.


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