The Universe is in a state of perpetual accelerated expansion, a phenomenon that has puzzled scientists for decades. Behind this mystery potentially lies an intriguing concept: the existence of an anti-Universe where time flows in reverse compared to ours. This theory could revolutionize our cosmic understanding.
Current theories, such as Lambda-CDM, rely on the cosmological constant to explain the accelerated expansion. However, this approach has significant theoretical gaps. This is why alternatives like quintessence or modified gravity theories have emerged, attempting to solve the enigma through various means, including postulating additional dimensions.
A new model proposes a radically different solution. Instead of relying on concepts of dark energy or gravitational modifications, it envisions a partner universe, an anti-Universe where time flows in the opposite direction. This idea, though innovative, has solid foundations in quantum physics and general relativity.
From a quantum perspective, it is conceivable that the Universe was born as a pair. Thus, according to CPT symmetry (Charge, Parity, and Time), the Universe after the Big Bang could be the reflection of the Universe before it. Boyle and his colleagues proposed that our Universe and its partner anti-Universe respect this symmetry, bringing a new dimension to our cosmic understanding.
Representation of a Universe/anti-Universe pair.
Credit: Wikipedia, CC Based on principles of general relativity like the zero-energy condition and quantum concepts such as relative entropy, it has been demonstrated that accelerated expansion is a natural consequence of this symmetry. Relative entropy, requiring two states, perfectly corresponds to the Universe and its anti-Universe, making this theory coherent and elegant.
Thus, according to this new theory, the accelerated expansion of our Universe could be intrinsically linked to the existence of a partner anti-Universe. This new approach, relying on established theories without resorting to hypothetical elements like dark energy, offers a potentially revolutionary perspective for modern cosmology.