Physicists have actually proposed a new analysis of dark energy. It might shed insight on the interconnection between quantum field theory and basic relativity theory, as two perspectives on deep space and its components.
What is behind dark energy– and what links it to the cosmological continuous introduced by Albert Einstein? 2 physicists from the University of Luxembourg point the way to addressing these open concerns of physics.
The universe has a variety of unusual homes that are tough to comprehend with daily experience. For instance, the matter we understand, consisting of primary and composite particles constructing materials and molecules, obviously makes up just a small part of the energy of the universe. The largest contribution, about two-thirds, comes from “dark energy”– a theoretical kind of energy whose background physicists are still confusing over. The universe is not just broadening steadily, but also doing so at an ever-faster speed.
Both qualities appear to be connected, due to the fact that dark energy is also thought about a motorist of accelerated expansion. It could reunite 2 effective physical schools of idea: quantum field theory and the basic theory of relativity established by Albert Einstein.
The trail of virtual particles in a vacuum
” Vacuum has energy. Its vital feature: in contrast to quantum mechanics, the theory considers not just particles however also matter-free fields as quantum objects.
” In this framework, many researchers regard dark energy as an expression of the so-called vacuum energy,” says Tkatchenko: a physical quantity that, in a vivid image, is brought on by a continuous emergence and interaction of sets of particles and their antiparticles– such as positrons and electrons– in what is actually empty area.
Cosmic microwave background seen by Planck. Credit: ESA and the Planck Collaboration
Physicists mention this reoccuring of virtual particles and their quantum fields as vacuum or zero-point changes. While the particle sets rapidly vanish into nothingness once again, their presence leaves a certain quantity of energy.
” This vacuum energy likewise has a significance in basic relativity,” the Luxembourg scientist notes: “It manifests itself in the cosmological continuous Einstein consisted of into his equations for physical reasons.”
A gigantic inequality
Unlike vacuum energy, which can just be deduced from the solutions of quantum field theory, the cosmological constant can be determined straight by astrophysical experiments. Measurements with the Hubble area telescope and the Planck space mission have actually yielded close and dependable values for the fundamental physical quantity. Estimations of dark energy on the basis of quantum field theory, on the other hand, yield results that represent a worth of the cosmological constant that is up to 10120 times bigger– a gigantic disparity, although in the world view of physicists dominating today, both worths ought to be equivalent. The inconsistency found instead is called the “cosmological consistent enigma.”
” It is unquestionably one of the biggest disparities in modern science,” says Alexandre Tkatchenko.
Unconventional method of analysis
Together with his Luxembourg research associate Dr. Dmitry Fedorov, he has now brought the option to this puzzle, which has actually been open for years, a significant step better. In a theoretical work, the results of which they just recently published in Physical Review Letters, the 2 Luxembourg scientists propose a brand-new analysis of dark energy. It presumes that the zero-point fluctuations lead to a polarizability of the vacuum, which can be both determined and computed.
” In sets of virtual particles with an opposite electrical charge, it occurs from electrodynamic forces that these particles exert on each other throughout their extremely short presence,” Tkatchenko describes. The physicists describe this as a vacuum self-interaction. “It leads to an energy density that can be determined with the help of a new model,” says the Luxembourg researcher.
Together with his research study colleague Fedorov, they established the standard model for atoms a couple of years ago and presented it for the very first time in 2018. The model was initially used to describe atomic homes, in specific the relation in between polarizability of atoms and the stability homes of particular non-covalently bonded solids and molecules. Considering that the geometric characteristics are quite simple to determine experimentally, polarizability can also be figured out through their formula.
To this end, the two scientists looked at the behavior of quantum fields, in particular representing the “coming and going” of electrons and positrons. The fluctuations of these fields can also be characterized by a stability geometry which is already understood from experiments.
The last step was then to quantum mechanically determine the energy density of the self-interaction in between fluctuations of electrons and positrons. The outcome acquired in this way concurs well with the measured worths for the cosmological constant. This suggests: “Dark energy can be traced back to the energy density of the self-interaction of quantum fields,” emphasizes Alexandre Tkatchenko.
Consistent worths and proven forecasts
” Our work therefore uses a elegant and unconventional approach to solving the riddle of the cosmological consistent,” sums up the physicist. “Moreover, it provides a verifiable forecast: namely, that quantum fields such as those of electrons and positrons do indeed possess an ever-present however small intrinsic polarization.”
This finding points the method for future experiments to spot this polarization in the laboratory also, state the 2 Luxembourg scientists. “Our objective is to derive the cosmological continuous from a strenuous quantum theoretical technique,” emphasizes Dmitry Fedorov. “And our work contains a dish on how to recognize this.”
He sees the brand-new results obtained together with Alexandre Tkatchenko as the very first action toward a much better understanding of dark energy– and its connection to Albert Einsteins cosmological constant.
Tkatchenko is encouraged: “In the end, this might likewise shed light on the way in which quantum field theory and general relativity theory are interwoven as two ways of looking at the universe and its elements.”
Recommendation: “Casimir Self-Interaction Energy Density of Quantum Electrodynamic Fields” by Alexandre Tkatchenko and Dmitry V. Fedorov, 24 January 2023, Physical Review Letters.DOI: 10.1103/ PhysRevLett.130.041601.
The biggest contribution, about two-thirds, comes from “dark energy”– a theoretical type of energy whose background physicists are still puzzling over. Unlike vacuum energy, which can only be deduced from the formulae of quantum field theory, the cosmological constant can be identified directly by astrophysical experiments. Estimations of dark energy on the basis of quantum field theory, on the other hand, yield results that correspond to a value of the cosmological constant that is up to 10120 times bigger– a gigantic disparity, although in the world view of physicists dominating today, both values need to be equal. The last step was then to quantum mechanically calculate the energy density of the self-interaction in between fluctuations of positrons and electrons. This suggests: “Dark energy can be traced back to the energy density of the self-interaction of quantum fields,” stresses Alexandre Tkatchenko.