A new model suggests that a companion antiuniverse could explain the accelerated expansion without the need for dark energy

The accelerated expansion of the current universe, believed to be driven by mysterious dark energy, is one of the biggest puzzles in our understanding of the universe. The Standard Model of cosmology, called Lambda-CDM, explains this expansion as a cosmological constant in Einstein’s field equations. However, the cosmological constant itself lacks a complete theoretical understanding, especially when it comes to its very small positive value.

To account for the accelerated expansion, physicists have proposed alternative explanations such as quintessence and modified theories of gravity, including scalar-tensor-vector gravity. Additionally, explanations beyond four dimensions, such as the braneworld scenarios in the Dvali-Gabadadze-Porrati (DGP) model, modify long-range gravity due to the effect of the larger dimension on our four-dimensional gate and the varying voltage of the gates.

My new model

In my work, I propose a different model to explain the current accelerated expansion of the universe. Unlike existing models, this does not require any form of dark energy or modified gravity approaches. But it’s a price to pay: we need a partner anti-universe whose time flow is in the opposite relation to our universe.

There are strong arguments to support this concept. From the point of view of quantum theory, it is natural that the universe originates in pairs. Recently, Boyle et al proposed that the universe does not spontaneously break CPT (charge, parity and time reversal symmetry), but that the universe after the Big Bang is the CPT image of the universe before it, pointing to a companion anti-universe.

Recent results

In a recent article published in Gravitation and Cosmology, I used key concepts from quantum theory, such as relative entropy, and from general relativity, such as the zero energy condition corresponding to the positive energy condition. My findings suggest that the universe is naturally expanding at an accelerated rate.

The relative entropy, which requires two states, corresponds in this case to the universe and its partner antiuniverse. Accelerated expansion appears to be inevitable in a universe created in pairs that respect the zero-energy condition. This result is quite surprising, and readers familiar with Hawking’s area theorem may notice certain similarities. The area theorem also deals with causal horizons and requires the zero energy condition to hold.

In our model, the causal horizon corresponds to the Big Bang. The results are equally valid for the partner antiverse.

In summary, the accelerated expansion of the universe is a challenging topic that continues to drive scientific efforts. My model builds on existing theories and offers an explanation using standard concepts from quantum theory and general relativity, without the need for the elusive dark energy.

The results suggest that accelerated expansion is natural to the universe created in pairs. Moreover, the study of causal horizons can deepen our understanding of the universe. The beauty of this idea lies in its simplicity and naturalness, which sets it apart from existing explanations.

This story is part of the Science X Dialog, where researchers can report findings from their published research articles. Visit this page for information on Science X Dialog and how to participate.