The cosmological constant and quantum vacuum. Alain Blanchard - PowerPoint PPT Presentation

Introduction Quantum Vacuum contribution A new scenario The cosmological constant and quantum vacuum. Alain Blanchard Arnaud Dupays, Brahim Lamine & A.B. A&A, 554 , A60 (2013) FFP14 Marseille, July 18th, 2014 Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Accelerated expansion There is no FL model that reproduces the present day observations without acceleration... Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Nobel Prize in Physics 2011 Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Nobel Prize in Physics 2011 S.Perlmuter, A.Riess, B.Schmidt Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario What does it mean? Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario What does it mean? Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario What does it mean? In GR, the source of gravity is ρ and P : ¨ R ∝ − ( ρ + 3 P ) R Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario What does it mean? In GR, the source of gravity is ρ and P : ¨ R ∝ − ( ρ + 3 P ) R Observations need P ≈ − ρ Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario What does it mean? In GR, the source of gravity is ρ and P : ¨ R ∝ − ( ρ + 3 P ) R Observations need P ≈ − ρ So that the gravity strength is repulsive and proportional to R ... Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Historical aspects Λ was introduced by Einstein Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Historical aspects Λ was introduced by Einstein Lemaître (1934) made the comment that Λ is equivalent to a Lorentz invariant non-zero vacuum, i.e. P = − ρ (1) Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Historical aspects Λ was introduced by Einstein Lemaître (1934) made the comment that Λ is equivalent to a Lorentz invariant non-zero vacuum, i.e. P = − ρ (1) Is there an experimental difference between Λ and L.I.V.? Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Historical aspects Λ was introduced by Einstein Lemaître (1934) made the comment that Λ is equivalent to a Lorentz invariant non-zero vacuum, i.e. P = − ρ (1) Is there an experimental difference between Λ and L.I.V.? Nerst (1916) and Pauli discussed the possible contribution of zero-point energy to the density of the Universe ( → Kragh arXiv:1111.4623 ) Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Historical aspects Λ was introduced by Einstein Lemaître (1934) made the comment that Λ is equivalent to a Lorentz invariant non-zero vacuum, i.e. P = − ρ (1) Is there an experimental difference between Λ and L.I.V.? Nerst (1916) and Pauli discussed the possible contribution of zero-point energy to the density of the Universe ( → Kragh arXiv:1111.4623 ) So is this the origin of the acceleration ? Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Historical aspects No! Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Historical aspects No! The Vacuum catastroph (Weinberg, 1989): � + ∞ 1 1 ρ v = � 0 | T 00 | 0 � = 2 � ω d 3 k ( 2 π ) 3 0 with ω 2 = k 2 + m 2 Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Historical aspects No! The Vacuum catastroph (Weinberg, 1989): � k c 1 1 ρ v = � 0 | T 00 | 0 � = 2 � ω d 3 k ( 2 π ) 3 0 with ω 2 = k 2 + m 2 highly divergent: k 4 c ρ v ( k c ) ∝ 16 π 2 (for k c ≫ m ). Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Equation of state The pressure (massless field): � + ∞ � 0 | T ii | 0 � = 1 1 � k d 3 k P v = ( 1 / 3 ) 2 ( 2 π ) 3 3 0 i Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Equation of state The pressure (massless field): � + ∞ � 0 | T ii | 0 � = 1 1 � k d 3 k P v = ( 1 / 3 ) 2 ( 2 π ) 3 3 0 i So that any regularization that is applied to both quantities leads to the e.o.s.: Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Equation of state The pressure (massless field): � + ∞ � 0 | T ii | 0 � = 1 1 � k d 3 k P v = ( 1 / 3 ) 2 ( 2 π ) 3 3 0 i So that any regularization that is applied to both quantities leads to the e.o.s.: P = 1 3 ρ (2) Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Equation of state The pressure (massless field): � + ∞ � 0 | T ii | 0 � = 1 1 � k d 3 k P v = ( 1 / 3 ) 2 ( 2 π ) 3 3 0 i So that any regularization that is applied to both quantities leads to the e.o.s.: P = 1 3 ρ (2) i.e. eq. (1) + eq. (2) leads to : P v = ρ v = 0 Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Equation of state The pressure (massless field): � + ∞ � 0 | T ii | 0 � = 1 1 � k d 3 k P v = ( 1 / 3 ) 2 ( 2 π ) 3 3 0 i So that any regularization that is applied to both quantities leads to the e.o.s.: P = 1 3 ρ (2) i.e. eq. (1) + eq. (2) leads to : P v = ρ v = 0 → usual conclusion on zero-point energy contribution (for instance by dimensional regularization). Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Equation of state Does not hold for a massive field (Zeldovich 1968, ...): P v = − ρ v Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Equation of state Does not hold for a massive field (Zeldovich 1968, ...): P v = − ρ v But ρ v = m 4 ( ... ) Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Equation of state Does not hold for a massive field (Zeldovich 1968, ...): P v = − ρ v But ρ v = m 4 ( ... ) cf Review by J.Martin 2012 (astro-ph/1205.3365). Everything You Always Wanted To Know About The Cosmological Constant Problem (But Were Afraid To Ask) Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Casimir effect Where is there vacuum contribution in laboratory physics? Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Casimir effect Where is there vacuum contribution in laboratory physics? Casimir effect Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Casimir effect Where is there vacuum contribution in laboratory physics? Casimir effect with (assuming ρ ext = 0): P x = 3 ρ Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Casimir effect Where is there vacuum contribution in laboratory physics? Casimir effect with (assuming ρ ext = 0): P x = 3 ρ < 0 Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Casimir effect Where is there vacuum contribution in laboratory physics? Casimir effect with (assuming ρ ext = 0): P x = 3 ρ < 0 and ... Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Casimir effect Where is there vacuum contribution in laboratory physics? Casimir effect with (assuming ρ ext = 0): P x = 3 ρ < 0 and ... P // = − ρ Brown & Maclay (1968) Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Casimir effect from higher dimension Assume there is an additional compact dimension. Alain Blanchard The cosmological constant and quantum vacuum.

Introduction Quantum Vacuum contribution A new scenario Casimir effect from higher dimension Assume there is an additional compact dimension. Standard physics in 3+1 D (brane), gravity in 3+1+1D (Bulk). Alain Blanchard The cosmological constant and quantum vacuum.