有效场论、全息原理 暴胀宇宙、暗能量 Yue-Liang Wu (吴岳良) State Key...
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Transcript of 有效场论、全息原理 暴胀宇宙、暗能量 Yue-Liang Wu (吴岳良) State Key...
有效场论、全息原理暴胀宇宙、暗能量
Yue-Liang Wu (吴岳良)State Key Laboratory of Theoretical Physics (SKLTP)
Kavli Institute for Theoretical Physics China ( KITPC )Institute of Theoretical Physics,
Chinese Academy of Sciences
2012.05.07
Universe 宇宙 Matter 物
质~ 30 %
Dark Energy
暗能量~ 70% Dark Matter
暗物质 85%
H (77%)
Quark Matter
夸克物质15%
He (23%)
宇宙组份宇宙组份
和谐宇宙学模型:以大爆炸宇宙学标准模型为基础的
暴胀暗能量暗物质夸克物质
暴胀
现代宇宙学模型
Effective Field Theory & Holographic Principle
An effective field theory that can saturate the equation necessarily includes many states with Schwarzschild radius much larger than the box size.
An effective quantum field theory is expected to be capable of describing a system at a temperature T , provided that T ≤ Λ , so long as T 1/L≫ .
Thermal energy
Entropy
The corresponding Schwarzschild radius
Entropy
To avoid these difficulties Cohen-Kaplan-Nelson propose a stronger constraint on the IR cutoff 1/L which excludes all states that lie within their Schwarzschild radius. Since the maximum energy density in the effective theory is Λ^4, the constraint on L is
Thermal energy ~ ~
Schwarzschild radius
Local quantum field theory appears unlikely to be a good effective low energy description of any system containing a black hole, and should probably not attempt to describe particle states whose volume is smaller than their corresponding Schwarzschild radius.
Holographic Principle: (Cohen-Kaplan-Nelson, PRL1999)
In Effective Field Theory, UV Cut-off is related to the IR Cut-off due to the limit set by the formation of a Black Hole
Effective Theory describes all states of system except those already collapsed to a Black Hole.
Vacuum energy density via quantum fluctuation
Effective Field Theory & Holographic Principle
Holographic Dark EnergyHolographic Dark Energy Model:
Dark energy density is given by the vacuum energy density caused via quantum fluctuation
Characteristic length scale of universe
Choosing different characteristic length scale L
Various Holographic Dark Energy Models
Review see: M. Li, X. -D. Li, S. Wang, Y. Wang, CTP. 56, 525-604 (2011) [arXiv:1103.5870].M. Li, Phys. Lett. B 603, 1 (2004) [arXiv:hep-th/0403127].R. -G. Cai, Phys. Lett. B 657, 228-231 (2007) [arXiv:0707.4049 [hep-th]].
Model parameter Reduced Planck mass
Holographic Dark Energy Characterized by Conformal-age-like Length (CHDE)
Z.P. Huang, YLW, arXiv:1202.2590,
Z.P. Huang, YLW, arXiv:1202.3517 [astro-ph.CO]
Conformal-age-like length scale of universe
Motivated from 4D space-time volume of FRW Universe
Holographic Dark Energy Characterized by Conformal-age-like Length (CHDE)
Fractional energy density of CHDE Friedman Equation
Equation of Motion of CHDEConservation of energy density Friedman equation
EoS for CHDE
Equation of motion for CHDE
Density with constant
CHDE
Solution of EoM for CHDE
At early time of universe
Assuming: Dark energy is negligible
Equation of motion for CHDE in a good approximation
Solution of EoM for CHDE consistency
Inflationary Universe & Conformal-age-like Length of CHDE
At early time of universe with Universe with constant
Conformal-age-like Length of CHDE
= -1
= 1/3
Consistent check from L
EoS of Dark Energy
Epoch: Inflation Radiation Matter Today <
CHDE is a single parameter (d) model like
Holographic Dark Energy Characterized by Total Comoving Horizon (ηHDE)
Z.P. Huang, YLW, arXiv:1202.2590, to be published in PRD
Holographic Dark Energy Characterized by Total Comoving Horizon (ηHDE)
Total comoving horizon of the universe
Characteristic Length Scale L of Universe from Causality
Energy density of holographic dark energy
Rescaled independent parameter & Fractional DE Density
Primordial part of comoving horizon generated by inflation
Comoving horizon in radiation- & matter-dominated epoch
grows
Total comoving horizon of the universe
Energy density & fractional energy density of dark energy
behaves like a cosmological constant
Fractional energy density of dark energy
Fraction of dark energy in matter-dominated epoch
New agegraphic dark energy (NADE) Avoid Divergence
C. -Y. Sun, R. -H. Yue, Phys. Rev. D 83, 107302 (2011) .
Equation of Motion of ηHDEConservation of energy density Friedman equation
EoS for ηHDE
Equation of motion for ηHDE
Density with constant
ηHDE
Relevant Cosmological Observations• Union2 compilation of 557 supernova Ia (SNIa) data, • Baryon acoustic oscillation (BAO) results from the Sloan
Digital Sky Survey data release 7 (SSDS DR7) , • Cosmic microwave background radiation (CMB) data from
7-yr Wilkinson Microwave Anisotropy Probe (WMAP7)• Hubble constant H measurement from the Wide Field
Camera 3 on the Hubble SpaceTelescope (HSTWFC3)
Likelihood function and Minimal
C.Q.Geng, C.C.Lee , E.N.Saridakis, JCAP 1201, 002 (2012) [arXiv:1110.0913 ]
Type Ia Supernovae (SN Ia) Theoretical Distance modulus
Hubble-free luminosity distance Minimal
Expand with respect to
Minimal with respect to
Baryon Acoustic Oscillations (BAO)Volume averaged distance Proper angular diameter distance
Comoving sound horizon
Fitting formula
Distance ratio of BAO Observation and analysis of BAO
Cosmic Microwave Background (CMB) Radiation
Acoustic scale Shift parameter
Redshift of the decoupling epoch
WMAP7 observations and analysis of CMB
SYSTEMATIC ANALYSIS ON CHDE MODEL
The statefinder parameter j− s contour evolves in redshift inteval z [−0.2; 15]∈ (The arrow indicatesthe evolution from high redshift to low redshift); Model parameters take the best-fit values, i.e.d = 0.235 r0 = 3.076 × 10−4
Best-Fit Results for ηHDE Model at 1σ (68.3%) and 2σ (95.4%)
Fractional Energy Density of Dark Matter
General Class of HDE Models
n=m=0, ADE; n=0,m=-1, ηHDE; n=4,m=3, CHDE
Z.P. Huang, YLW arXiv:1205.0608 [gr-qc]
The minimum of by using only the Union2 SNIa data; for comparison,
The best-fit results of some models with n - m = 1 by using only the Union2 SNIa data
The best-fit by using SNIa+BAO+CMB data sets; for comparison
The best-fit results at (68.3%) and (95.4%) confidence levels by using SNIa+BAO+CMB data sets;
Holographic Dark Energy Cosmological Constant
Understanding Fine-tuning Problem & Coincidence Problem
Inflationary Universe Accelerated Universe
Holographic Principle
Summary
暗物质和暗能量二十世纪末物理学和天文学晴朗天空中的“两朵乌云”
引力相互作用 与能量有关 与物质和运动有关(加速膨胀) 与真空有关(宇宙常数)
世纪难遇的重大科学问题:
理解暗物质和暗能量问题同样需要发展和建立新的理论,一旦取得突破,将带来一场重大的物理学和天文学革命。
与粒子物理和量子场论所涉及到的最基本的关键问题密切相关,如真空和对称破缺机制,新的基本粒子和物质形态
量子引力、物质时空统一理论:必将引发二十一世纪宇宙起源等基本问题有更深的认识
新的“两朵乌云”
“ 两朵乌云”
电磁相互作用
• 与能量有关• 与物质和运动有关• 与真空有关(以太说 )
1900 年,开尔文:“ There is nothing new to be discovered in physics now. All that remains is more and more precise measurement.” ,“ Two small, puzzling clouds remained on the horizon” ——黑体辐射实验和迈克尔逊 - 莫雷实验
十九世纪末物理学晴朗天空中的“两朵乌云”,给物理学带来了革命性变革,导致“新理论”的发现——“量子论”和“相对论”,极大地推进了人类对物质世界的认识。
热辐射物体能量随发光波长分布:维恩公式和瑞利一金斯公式分别在长波和短波与实验结果不符