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Entropic Gravity. SISSA, Statistical Physics JC Friday 28, 2011. E. Verlinde , arXiv : 1003.4464v2 [ hep-th ]. F. Entropy. Outlook. Background: Holographic Principle (Black Hole Thermodynamics , Entropy Bound ) Verlinde argument for an entropic gravity
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EntropicGravity SISSA, Statistical Physics JC Friday 28, 2011 E. Verlinde, arXiv: 1003.4464v2 [hep-th]
F Entropy
Outlook • Background: HolographicPrinciple (Black HoleThermodynamics, EntropyBound) • Verlindeargument for an entropicgravity (II principle of dynamics, Newton’s law of gravity) • … editorialdiscussion
Hawking (1971) Bekenstein (1972) Black body radiation Hawking (1973)
= R Bekenstein (1981) E A Susskind (1995)
Toward the holographicprinciple… Number of degrees of freedom Ex 1 100 bits of information Ex 2 ! Ex 3 Quantum fieldtheory Voscillators and nstates per oscillator
How manydifferentstates can be in a region to describeall the physics inside of it? Whatis the entropy of the «fundamentalsystem»? A region with boundary of area A isfullydescribed by no more than A/4 degrees of freedom, or about 1 bit of information per Planck area
Outlook • Background: HolographicPrinciple (Black HoleThermodynamics, EntropyBound) • Verlindeargument for an entropicgravity (II principle of dynamics, Newton’s law of gravity) • … editorialdiscussion
SPACE asa storage of information 110 011 110 010 001 111 101 001 … nothingyet… Emergedspace Holographic screen Wefurther assume the theoryhas a notion of time and thatitsdynamicsistraslationalinvariant Energy Temperature Stat. Phys.
Force and Inertia Holographic screen UnruhEffect
Newton’s law of gravity Holographicprinciple T
The number of degrees of freedomisproportional to the area of the screen (Holographicprinciple) The energyisevenlydistributed over thesedegrees of freedom (iii) Thereis a change of entropy in the emergentdirection Bekenstein + Unruh
ɸis a coarse-grainingvariable Amount of coarsegraining Coarse- Graining Space isemerging!
Dark Energy radius of the observableuniverse holographicprinciple
UnruhEffect Itworks for dimensionalconsistency!
References • E. Verlinde‘On the origin of Gravity and the Newton laws’ • S.GaoComment on "On the Origin of Gravity and the Laws of Newton" • A. Chivukula‘Gravity as an entropic phenomenon’ • T. Jacobson, ‘Thermodynamics of Spacetime’ Phys. Rev. Lett. (1995) • R. Bousso ‘The holographic principle’ • R. Ruffiniand H. Ohanian ‘Gravitation and spacetime’