While Einstein’s theory of general relativity may explain many interesting astrophysical and cosmological phenomena, some aspects of the properties of the universe remain a mystery on a large scale. A new study using loop quantum cosmology, a theory that uses quantum mechanics to extend gravitational physics beyond Einstein’s theory of general relativity, explains two major mysteries. Although the differences in theories occur on the smallest scale — much smaller even than the proton — they have implications on the largest scales available in the Universe. The study, which appears online in the magazine on July 29th Physical review writings, also provides new predictions of the universe for future satellite missions.
Although the distorted view of the universe looks fairly uniform, it has a large structure, for example, because galaxies and dark matter are not evenly distributed throughout the universe. The origin of this structure is traced to the small inhomogeneities observed in cosmic microwave background (CMB) radiation that was emitted when the Universe was 380,000 years young, which we can still see today. But CMB itself has three enigmatic features that are considered anomalies because they are difficult to explain using known physics.
“While seeing one of these anomalies may not be so amazing, seeing two or more together, we can live in an exceptional universe,” said Donghui Jeong, Penn State’s associate professor of astronomy and astrophysics and author of the article. “A recent study in the journal Nature Astronomy suggested explaining one of these anomalies, which caused so many additional concerns. They noted a “possible cosmological crisis.” By applying quantum loop cosmology, we have actually eliminated two of these anomalies naturally, avoiding a possible crisis.
Research over the past three decades has greatly improved our understanding of the early universe, including how CMB inhomogeneity first emerged. These inhomogeneities are the result of inevitable quantum fluctuations in the early universe. In a very accelerated stage of development, in the very early days, called inflation, these primordial, low-value fluctuations were stretched by the action of gravity and gave the observed heterogeneity to the CMB.
“To understand how primordial seeds came into being, we need to take a closer look at the early universe that breaks down Einstein’s theory of general relativity,” said Abhay Ashtekar, physics professor at Evan Pugh, owner and director of the Eberly family chair in physics. Penn State Institute of Gravity and Space. “The usual inflation paradigm, based on general relativity, treats space-time as a smooth continuity. Consider shirts that look like a two-dimensional surface, but on closer inspection you can see that they are woven with densely packed one-dimensional yarns. By computing these threads, quantum quantum cosmology allows us to transcend the continuity described in general relativity, where Einstein’s physics decomposes, for example, outside the Big Bang. “
Previous scholarly research on the early universe replaced the idea of the uniqueness of the Big Bang when the Universe came out of nowhere, with the Big Bang when the current expanding universe came from the highly compressed mass that was created when the Universe shrank its previous phase. They found that all large-scale universe structures represented by general relativity are equally explained by inflation after this large rebound, using the equations of the quantum cosmology of the loops.
In a new study, researchers found that inflation in quantum quantum cosmology solves two major anomalies in general relativity features.
“The primary fluctuations we’re talking about happen on an incredibly small Planck scale,” said Brajes Gupt, a postdoctoral researcher in Pennsylvania who is currently working at the University of Texas at Texas Advanced Computing Center in Austin. “Planck’s length is about 20 times smaller than the proton’s radius. But inflation adjustments on such an unimaginably small scale simultaneously explain two anomalies on the largest universe scales in space, very small and very large.”
The researchers also provided new predictions about key cosmological parameters and primitive gravitational waves that could be tested during future satellite missions, including LiteBird and Cosmic Origins Explorer, which will further improve our understanding of the early universe.
The shape of the universe: study could force us to rethink everything we know about space
Abhay Ashtekar et al., Easing tension in the cosmic microwave background using Planck scale physics, Physical review writings (2020). DOI: 10.1103 / PhysRevLett.125.051302
Provided by Pennsylvania State University
Citation: Cosmic Tango Between Very Low and Very High (2020, July 30) July 30 From https://phys.org/news/2020-07-cosmic-tango-small-large.html
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