Gravity is attractive, therefore, after the Big Bang, the expansion of the Universe is expected to decelerate (i.e. slow down) due to the attractive nature of gravity. In 1998 astrophysical measurements of supernova explosions surprisingly indicated that, during the last 7 billion years, the expansion of the Universe is accelerating, rather than decelerating. This acceleration of the Universe is a type of repulsive gravity. In the LCDM cosmological model, this repulsive gravity is attributed to a cosmological constant L or, more generally, Dark Energy, which is a property of empty space. L is an adjustable parameter in the LCDM model, with no explanation for either its magnitude or physical properties.

In recent publications (Astrophys. Space Sci. 365:64 (2020), Phys. Sci. Forum 2(1):9 (2021)) the author has developed a new theory for DE that attributes this repulsive gravity to the energy contained within the electric field that surrounds a finite-sized electron in intergalactic space. This theory provides a quantitative explanation for both DE’s magnitude, as well as, many of its physical attributes. Additionally, this finite-sized electron model predicts the occurrence of a glass transition, pico-seconds after the Big Bang, when electrons and positrons are in physical contact with each other, due to their finite-size. This glass transition gives rise to an exponential acceleration of the Universe (Sci. Rep. 13, 21798 (2023)) possessing many of the characteristics attributed to Cosmic Inflation (CI). In standard cosmology CI occurs at times earlier than the LCDM model where CI is required in order to explain the flatness, homogeneity, and isotropy of the Cosmic Microwave Background. In this talk we first briefly describe this new theory for DE; the majority of the talk will be spent outlining the exponential acceleration picoseconds after the Big Bang, with characteristics similar to CI.

(Note: The concepts used in this colloquium should be accessible to anyone with a general Physics background.)

Bruce Law obtained his PhD in Physics under Professor David Beaglehole from Victoria University in Wellington, New Zealand in 1985. He did a postdoc at the University of Maryland, College Park, Maryland, USA from 1985-1989 under Professors Jan Sengers and Bob Gammon. In 1989 he was hired as an Assistant Professor of Physics at Kansas State University in Manhattan, Kansas, USA. In 2011 he was elected as a Fellow of the American Physical Society for his contributions to the understanding of surface phase transitions and surface critical phenomena in liquids. Dr Law retired from his position as a Professor of Physics at Kansas State University in 2021 and is currently an Emeritus Professor of this institution. During his career Dr Law was recognized for his experimental studies of non-equilibrium thermal fluctuations in liquids, surface tension and line tension phenomena in liquids, as well as, thermally induced phase transitions in liquids. He has used a variety of experimental techniques to study liquid phenomena including light scattering and ellipsometry, X-ray and neutron reflectometry, surface tensiometry, and atomic force microscopy. He is known for developing a close interconnection between theory and experiment.

Since 2013 Dr Law has been applying his knowledge of Soft Matter Physics to the field of Cosmology. In particular, in Soft Matter Physics, the solubility of ions in liquids is determined by the Born self-energy of the ion (UB), which corresponds to the energy contained within the electric field that surrounds an ion. UB ~ 1/R where R is the ionic radius. In Quantum Electrodynamics (QED) the electron is assumed to be a point particle (R  0); thus, the electron Born self-energy UBe is divergent where this divergence is eliminated in QED by assuming that UBe is subsumed (or contained) within the electron rest mass me. The treatment of electrons and ions is therefore inconsistent with each other. The only way to remove this inconsistency is if electrons possess a finite, non-zero radius, which would thus enable the solubility of electrons in liquids to be explained using UBe. In 2020 Dr Law demonstrated that the Born self-energy of electrons UBe, in intergalactic space, quantitatively agrees with the properties attributed to Dark Energy (DE). DE is causing the expansion of the Universe to accelerate during the last 7 billion years.