Einstein’s theory of relativity states that space and time are interdependent. The curvature of space-time in our universe is relatively small and constant. However, researchers from the University of Heidelberg have successfully created a laboratory experiment in which the space-time structure can be manipulated.

Einstein’s theory of relativity states that space and time are interdependent. The curvature of space-time in our universe is relatively small and constant. However, researchers from the University of Heidelberg have successfully created a laboratory experiment in which the space-time structure can be manipulated.

Researchers used ultracold quantum gases to model a series of warped universes to explore different cosmological scenarios. They then compared these simulations with the predictions of the quantum field model. The results of the research were published in the journal Nature.

The origin of space and time on cosmic time scales from the Big Bang to the present is the subject of ongoing research that can only be based on observations of our single universe. The expansion and distortion of space are important to cosmological models. In flat space like our current universe, the shortest distance between two points is always a straight line. “However, it is possible that our universe was warped in its early stages.

Therefore, the study of the consequences of warped space-time is an urgent issue in research studies,” says Professor Markus Oberthaler, a researcher at the Kirchhoff Institute for Physics at Heidelberg University. The research group, together with “Synthetic Quantum Systems”, has developed a quantum field simulator for this purpose.

A lab-built quantum field simulator consists of a cloud of potassium atoms cooled to just a few nanokelvins of absolute zero. As a result, a Bose-Einstein condensation is formed, which is a special quantum-mechanical state of an atomic gas obtained at very low temperatures.

Professor Oberthaler explains that the Bose-Einstein condensate is an ideal background where the smallest excitations, i.e. changes in the energy state of atoms, become visible. The shape of the atomic cloud determines the size and properties of the space-time through which these excitations are carried like waves. In our universe, space has three dimensions and a fourth: time.

In an experiment by Heidelberg physicists, atoms were trapped in a thin layer. Thus, excitations can only propagate in two spatial directions – space is two-dimensional. However, the atomic cloud in the other two dimensions can be formed in almost any shape, and with it, a warped space-time can also be realized. The interaction between atoms can be precisely regulated with the aid of a magnetic field, which changes the propagation speed of wave-like excitations in the Bose-Einstein condensate.

“The propagation velocity for waves on condensation depends on the density and interaction of the atoms. This gives us the opportunity to create conditions similar to those of an expanding universe,” explains Professor Stephan Flerhinger. The researcher, who previously worked at the University of Heidelberg and joined the University of Jena earlier this year, has developed a quantum field theory model that is used to quantitatively compare experimental results.

Using a quantum field simulator, cosmic phenomena such as the formation of particles based on the expansion of space and even the curvature of space-time can be made measurable. “Cosmological problems often occur on incredibly large scales. The ability to study them specifically in the lab opens up entirely new possibilities in research, allowing us to experimentally test new theoretical models,” he says. Nature.

“It will take some time to study the interaction of warped space-time and quantum mechanics states in the lab,” says Markus Oberthaler, whose research group is also part of the STRUCTURES Cluster of Excellence at Ruperto Caroli.