Atom-field dynamics in curved spacetime

Some aspects of atom-field interactions in curved spacetime are reviewed.Of great interest are quantum radiative and entanglement processes arising out of Rindler and black hole spacetimes,which involve the role of Hawking-Unruh and dynamical Casimir effects.Most of the discussion surrounds the radiative part of interactions.For this,we specifically reassess the conventional understandings of atomic radiative transitions and energy level shifts in curved spacetime.We also briefly outline the status quo of entanglement dynamics study in curved spacetime,and highlight literature related to some novel insights,like entanglement harvesting.On one hand,the study of the role played by spacetime curvature in quantum radiative and informational phenomena has implications for fundamental physics,notably the gravity-quantum interface.In particular,one examines the viability of the Equivalence Principle,which is at the heart of Einstein’s general theory of relativity.On the other hand,it can be instructive for manipulating quantum information and light propagation in arbitrary geometries.Some issues related to nonthermal effects of acceleration are also discussed.

From Yang-Mills Photon in Curved Spacetime to Dark Energy Density

We start from quantum field theory in curved spacetime to derive a new Einstein-like energy mass relation of the type E=γmc2 where γ=1/22 is a Yang-Mills Lorentzian factor, m is the mass and c is the velocity of light. Although quantum field in curved spacetime is not a complete quantum gravity theory, our prediction here of 95.4545% dark energy missing in the cosmos is almost in complete agreement with the WMAP and supernova measurements. Finally, it is concluded that the WMAP and type 1a supernova 4.5% measured energy is the ordinary energy density of the quantum particle while the 95.5% missing dark energy is the energy density of the quantum wave. Recalling that measurement leads to quantum wave collapse, it follows that dark energy as given by E(D) = mc2 (21/22) cannot be detected using conventional direct measurement although its antigravity effect is manifested through the increasing rather than decreasing speed of cosmic expansion.

Study of scalar particles through the Klein–Gordon equation under rainbow gravity effects in Bonnor–Melvin-Lambda space-time

In our investigation,we explore the quantum dynamics of charge-free scalar particles through the Klein–Gordon equation within the framework of rainbow gravity,considering the Bonnor–Melvin-Lambda(BML)space-time background.The BML solution is characterized by the magnetic field strength along the axis of the symmetry direction which is related to the cosmological constantΛand the topological parameterαof the geometry.The behavior of charge-free scalar particles described by the Klein–Gordon equation is investigated,utilizing two sets of rainbow functions:(i)f(χ)=■,h(χ)=1 and(ii)f(χ)=1,h(χ)=1+βХ/2.Here 0<(Х=■)≤1 with E representing the particle's energy,Ep is the Planck's energy,andβis the rainbow parameter.We obtain the approximate analytical solutions for the scalar particles and conduct a thorough analysis of the obtained results.Afterwards,we study the quantum dynamics of quantum oscillator fields within this BML space-time,employing the Klein–Gordon oscillator.Here also,we choose the same sets of rainbow functions and obtain the approximate eigenvalue solution for the oscillator fields.Notably,we demonstrate that the relativistic approximate energy profiles of charge-free scalar particles and oscillator fields get influenced by the topology of the geometry and the cosmological constant.Furthermore,we show that the energy profiles of scalar particles receive modifications from the rainbow parameter and the quantum oscillator fields by both the rainbow parameter and the frequency of oscillation.

Geometric Backreaction of Modified Quantum Vacua and Diffeomorphrisim Covariance

In this paper I have shown that squeezed modified quantum vacua have an effect on the background geometry by solving the semi-classical Einstein Field Equations in modified vacuum. The resultant geometry is similar to (anti) de Sitter spacetime. This geometry could explain the change of causal structure—speed of light—in such vacua without violating diffeomorphism covariance or causality. The superluminal propagation of photons in Casimir vacuum is deduced from the effective electromagnetic action in the resultant curved geometry. Singling between different vacua is shown not to violate causality as well when the geometric effect on the null rays is considered, causing a refraction of those rays when traveling between unbounded and modified vacua.

时间延缓效应在不同种类时钟中的体现

讨论了广义相对论描述的强引力场中的时间延缓效应是否可用任何类型的时钟验证的问题.通过论证得出结论:引力场中的时钟的快慢取决于时钟自身的工作原理,并非时间变快或者变慢所致.单摆钟在强引力场中所测时间变快,是由于强引力使单摆摆动的物理过程加快,非时间变快所致;同理,原子钟在强引力场中所测时间变慢,是由于强引力使原子能级发生变化,从而导致原子辐射的物理过程变慢,亦非时间变慢所致.最后,探讨了时钟与时间的本质问题.

The Solution Cosmological Constant Problem

The cosmological constant problem arises because the magnitude of vacuum energy density predicted by the Quantum Field Theory is about 120 orders of magnitude larger then the value implied by cosmological observations of accelerating cosmic expansion. We pointed out that the fractal nature of the quantum space-time with negative Hausdorff-Colombeau dimensions can resolve this tension. The canonical Quantum Field Theory is widely believed to break down at some fundamental high-energy cutoff and therefore the quantum fluctuations in the vacuum can be treated classically seriously only up to this high-energy cutoff. In this paper we argue that the Quantum Field Theory in fractal space-time with negative Hausdorff-Colombeau dimensions gives high-energy cutoff on natural way. We argue that there exists hidden physical mechanism which cancels divergences in canonical QED4, QCD4, Higher-Derivative-Quantum gravity, etc. In fact we argue that corresponding supermassive Pauli-Villars ghost fields really exist. It means that there exists the ghost-driven acceleration of the universe hidden in cosmological constant. In order to obtain the desired physical result we apply the canonical Pauli-Villars regularization up to &Lambda;*. This would fit in the observed value of the dark energy needed to explain the accelerated expansion of the universe if we choose highly symmetric masses distribution between standard matter and ghost matter below the scale &Lambda;*, i.e., The small value of the cosmological constant is explained by tiny violation of the symmetry between standard matter and ghost matter. Dark matter nature is also explained using a common origin of the dark energy and dark matter phenomena.

再论弯曲时空中的量子场论的新构想

通过坐标时和固有时的关系式,由度规表达式导出时空膨胀公式,得到由度规直接读出时空膨胀公式的方法,然后利用平移算符,将时空膨胀效果体现在平直时空的量子场论中。最后讨论在弯曲时空参考系中进行量子实验,以康普顿散射为例,考虑引力场导致的粒子产生与湮灭,给出一个适用的光子和引力场耦合的相互作用拉氏密度(半经典理论)。

Unification Might Be Achievable by a Hypothesis of Instantaneous Time-Jumps during Photon and Graviton Interactions (A Brief Note)

Quantum theory according to the Copenhagen interpretation holds that, when a quantum interaction is observed (i.e., “measured”), the observer’s measuring devices temporarily become a part of the quantum system. Relativity theory holds that the event clock of the absorbed or emitted photon or graviton is frozen in time relative to all clocks outside the observed system. If we harmonize both theories, this would appear to imply that time continuity must be interrupted at each instant of observed photon or graviton interaction with matter. It is as if a segment of space-time is clipped out during each such observed interaction. If so, we must dispense with the notion of an absolutely smooth and continuous space-time and replace it with an observation-dependent, discontinuous, relativistic/quantum space-time. Mathematical physicists should be able to model this hypothesis (call it a “time-jump hypothesis”) and its inherent discontinuous space-time in their further efforts at unification.

Entanglement dynamics in κ-deformed spacetime

We treat two identical and mutually independent two-level atoms that are coupled to a quantum field as an open quantum system.The master equation that governs their evolution is derived by tracing over the degree of freedom of the field.With this,we compare the entanglement dynamics of the two atoms moving with different trajectories inκ-deformed and Minkowski spacetimes.Notably,when the environment-induced interatomic interaction does not exist,the entanglement dynamics of two static atoms inκ-deformed spacetime are reduced to that in Minkowski spacetime in the case that the spacetime deformation parameterκis sufficiently large as theoretically predicted.However,if the atoms undergo relativistic motion,regardless of whether inertial or non-inertial,their entanglement dynamics inκ-deformed spacetime behave differently from that in Minkowski spacetime even whenκis large.We investigate various types of entanglement behavior,such as decay and generation,and discuss how different relativistic motions,such as uniform motion in a straight line and circular motion,amplify the differences in the entanglement dynamics between theκ-deformed and Minkowski spacetime cases.In addition,when the environment-induced interatomic interaction is considered,we find that it may also enhance the differences in the entanglement dynamics between these two spacetimes.Thus,in principle,one can tell whether she/he is inκ-deformed or Minkowski spacetime by checking the entanglement behavior between two atoms in certain circumstances.

Covariant spin kinetic theory I:collisionless limit

We develop a covariant kinetic theory for massive fermions in a curved spacetime and an external electromagnetic field based on quantum field theory.We derive four coupled semi-classical kinetic equations accurate to O(ℏ),which describe the transports of particle number and spin degrees of freedom.The relationship with chiral kinetic theory is discussed.As an application,we study spin polarization in the presence of finite Riemann curvature and an electromagnetic field in both local and global equilibrium states.

Hawking radiation of Dirac particles from soft-hairy black holes

In this paper,we study the Hawking radiation of Dirac particles via tunneling formalism from linearly supertranslated Schwarzschild black holes.We find that the radiation spectrum and the Hawking temperature remain the same as the one without soft hair.