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marcus

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http://arxiv.org/abs/1603.08658

**The Atoms Of Space, Gravity and the Cosmological Constant**

T. Padmanabhan

(Submitted on 29 Mar 2016)

I describe an approach which

**connects classical gravity with the quantum microstructure of spacetime**. The field equations arise from maximizing the density of states of matter plus geometry. The former is identified using the thermodynamics of null surfaces while

**the latter arises due to the existence of a zero-point length in the spacetime.**The resulting field equations remain invariant when a constant is added to the matter Lagrangian, which is a symmetry of the matter sector. Therefore,

**the cosmological constant arises as an integration constant.**A non-zero value Λ of the cosmological constant renders the amount of cosmic information (Ic) accessible to an eternal observer finite and hence is directly related to it.

**This relation allows us to determine the numerical value of Λ from the quantum structure of spacetime.**

Invited Review; 32 pages; 3 figures

==quote==

Substituting this into Eq. (59), we get a remarkable formula for the cosmological constant

...

...

If we take the typical values ρ

_{in}= (1.2 × 10

^{15}GeV)

^{4}, ρ

_{eq}= (0.86 eV)

^{4}, we get ρ

_{Λ }= (2.2 × 10

^{−3}eV)

^{4}

**which agrees well with observed value!**In other words, the idea that the cosmic information content accessible to an eternal observer, I

_{c}, is equal to the basic quantum gravitational unit of information I

_{QG}= 4π, determines the numerical value of the cosmological constant correctly. ...

==endquote==