Dark Energy May Be Incompatible With String Theory

Article by
String theory permits a “landscape” of possible universes, surrounded by a “swampland” of logically inconsistent universes. In all of the simple, viable stringy universes physicists have studied, the density of dark energy is either diminishing or has a stable negative value, unlike our universe, which appears to have a stable positive value.


Reprinted from Quanta Magazine.

A controversial new paper argues that universes with dark energy profiles like ours do not exist in the “landscape” of universes allowed by string theory.

On June 25, Timm Wrase awoke in Vienna and groggily scrolled through an online repository of newly posted physics papers. One title startled him into full consciousness.

The paper, by the prominent string theorist Cumrun Vafa of Harvard University and collaborators, conjectured a simple formula dictating which kinds of universes are allowed to exist and which are forbidden, according to string theory. The leading candidate for a “theory of everything” weaving the force of gravity together with quantum physics, string theory defines all matter and forces as vibrations of tiny strands of energy. The theory permits some 10500 different solutions: a vast, varied “landscape” of possible universes. String theorists like Wrase and Vafa have strived for years to place our particular universe somewhere in this landscape of possibilities.

But now, Vafa and his colleagues were conjecturing that in the string landscape, universes like ours — or what ours is thought to be like — don’t exist. If the conjecture is correct, Wrase and other string theorists immediately realized, the cosmos must either be profoundly different than previously supposed or string theory must be wrong.

After dropping his kindergartner off that morning, Wrase went to work at the Vienna University of Technology, where his colleagues were also buzzing about the paper. That same day, in Okinawa, Japan, Vafa presented the conjecture at the Strings 2018 conference, which was streamed by physicists worldwide. Debate broke out on- and off-site. “There were people who immediately said, ‘This has to be wrong,’ other people who said, ‘Oh, I’ve been saying this for years,’ and everything in the middle,” Wrase said. There was confusion, he added, but “also, of course, huge excitement. Because if this conjecture was right, then it has a lot of tremendous implications for cosmology.”

Researchers have set to work trying to test the conjecture and explore its implications. Wrase has already written two papers, including one that may lead to a refinement of the conjecture, and both mostly while on vacation with his family. He recalled thinking, “This is so exciting. I have to work and study that further.”

The conjectured formula — posed in the June 25 paper by Vafa, Georges Obied, Hirosi Ooguri and Lev Spodyneiko and further explored in a second paper released two days later by Vafa, Obied, Prateek Agrawal and Paul Steinhardt — says, simply, that as the universe expands, the density of energy in the vacuum of empty space must decrease faster than a certain rate. The rule appears to be true in all simple string theory-based models of universes. But it violates two widespread beliefs about the actual universe: It deems impossible both the accepted picture of the universe’s present-day expansion and the leading model of its explosive birth.

To read the complete article visit: https://www.quantamagazine.org/dark-energy-may-be-incompatible-with-string-theory-20180809/

Total
0
Shares

The Dangers of Quantum Tech

Article by ,

The United Nations has proclaimed 2025 as the International Year of Quantum Science and Technology

Indigenous Futurism?

Article by

National Geographic Explorer Keolu Fox says the key to harnessing the technology of tomorrow is centering traditions of the past

Magic Died When Art and Science Split

Article by

Renée Bergland’s 3 greatest revelations while writing Natural Magic: Emily Dickinson, Charles Darwin, and the Dawn of Modern Science

Quantum physics reveals the unity of the universe

Article by

Quantum physics revives the ancient idea of universal oneness that Christianity unjustly excluded from our culture

#77 Regenerative Medicine

Podcast with

Exploring the frontiers of alternative medicine and healing modalities with renowned Cerebral Spiral Fluid expert.

Pixels, Patterns & Perspectives

Video with

Physicist and Author Sky Nelson-Isaacs urges us to see the world differently and consider how pixels and patterns converge to evoke a new perspective.

Time to Support Indigenous Science

Article by

Faced with the profound challenges of a rapidly changing environment, society needs other ways of knowing to illuminate a different way forward

Resonantly Perfect Solar System Found

Article by

Researchers have located "the perfect solar system", forged without the violent collisions that made our own a hotchpotch of different-sized planets

Support SAND with a Donation

Science and Nonduality is a nonprofit organization. Your donation goes towards the development of our vision and the growth of our community.
Thank you for your support!