Lifeboat Foundation

If there are energy fluctuations in a quantum vacuum, very interesting things can happen. For example, the E = mc² relation tells us that energy and matter are interconvertible. A vacuum energy fluctuation can be converted into particles of matter. Sounds weird? Maybe, but it happens all the time. These particles are called virtual particles, living a fleeting existence before plunging back into the ever-busy quantum vacuum.

Tryon extrapolated the idea of quantum fluctuations to the Universe as a whole. He reasoned that if all that existed was a quantum vacuum, a bubble-like energy fluctuation out of this vacuum could have given rise to the Universe. Tryon proposed that the whole Universe is the result of a vacuum fluctuation, originating from what we could call quantum nothingness.

From eyeglasses to space telescopes, lenses play crucial roles in technologies ranging from the mundane to the cutting edge. While traditional refractive lenses are a fundamental building block of optics, they are bulky and this can restrict how they are used. Metalenses are much thinner than conventional lenses and in the last two decades plenty of light has been shone on the potential of these devices, which sparkle as a promising alternative.

Metalenses are thin structures made of arrays of “meta-atoms”, which are motifs with dimensions that are smaller than the wavelength of light. It is these meta-atoms that interact with light and change its direction of propagation.

Unlike conventional refractive lenses, metalenses can be less than one micron thick, reducing the overall volume of optical systems. They can also provide ideal diffraction-limited focusing performance, while avoiding some problems associated with refractive lenses such as aberrations.

When most people think of crystals, they picture suncatchers that act as rainbow prisms or the semi-transparent stones that some believe hold healing powers. However, to scientists and engineers, crystals are a form of materials in which their constituents—atoms, molecules, or nanoparticles—are arranged regularly in space. In other words, crystals are defined by the regular arrangement of their constituents. Common examples are diamonds, table salt, or sugar cubes.

However, in research just published in Soft Matter, a team led by Rensselaer Polytechnic Institute’s Sangwoo Lee, associate professor in the Department of Chemical and Biological Engineering, discovered that crystal structures are not necessarily always regularly arranged. The discovery advances the field of materials science and has unrealized implications for the materials used for semiconductors, solar panels, and electric vehicle technologies.

One of the most common and important classes of crystal structures is the close-packed structures of regular spheres constructed by stacking layers of spheres in a honeycomb arrangement. There are many ways to stack the layers to construct close-packed structures, and how nature selects specific stacking is an important question in materials and physics research. In the close-packing construction, there is a very unusual structure with irregularly spaced constituents known as the random stacking of two-dimensional hexagonal layers (RHCP). This structure was first observed from cobalt metal in 1942, but it has been regarded as a transitional and energetically unpreferred state.

Scientists at EPFL have found a new way to create a crystalline structure called a “density wave” in an atomic gas. The findings can help us better understand the behavior of quantum matter, one of the most complex problems in physics. The research was published May 24 in Nature.

“Cold atomic gases were well known in the past for the ability to ‘program’ the interactions between atoms,” says Professor Jean-Philippe Brantut at EPFL. “Our experiment doubles this ability.” Working with the group of Professor Helmut Ritsch at the University of Innsbruck, they have made a breakthrough that can impact not only quantum research but quantum-based technologies in the future.

Scientists have long been interested in understanding how materials self-organize into complex structures, such as crystals. In the often-arcane world of quantum physics, this sort of self-organization of particles is seen in “density waves,” where particles arrange themselves into a regular, repeating pattern or order; like a group of people with different colored shirts on standing in a line but in a pattern where no two people with the same color shirt stand next to each other.

A curved “laser wakefield accelerator” could boost the acceleration potential of a multistage version of this device.

Laser wakefield accelerators (LWFAs) use laser-generated plasmas to accelerate electrons to high energies. The devices are significantly smaller than radio-frequency-based particle accelerators—centimeters versus hundreds of meters—making them less expensive, more efficient alternatives. But researchers still need to demonstrate that LWFAs can achieve particle energies that match those of their conventional counterparts. Now Xinzhe Zhu from Shanghai Jiao Tong University and colleagues have brought that goal a step closer, demonstrating a method for linking multiple LWFAs in a way that would boost their acceleration potential [1].

In an LWFA, charged particles reach relativistic speeds by surfing a wave of plasma created by a powerful laser. The particle energy achievable with a single LWFA is limited to a few GeV for two reasons: the particle bunch and the plasma wave quickly fall out of sync, and the laser energy dissipates with distance. Routing particles through multiple connected LWFAs would overcome these problems. But current techniques for combining LWFAs require refocusing the beam at each connection, lowering the efficiency of the process.

Researchers in the US have developed a machine learning algorithm that accurately reconstructs the s.

It may be that the famous Higgs boson, co-responsible for the existence of masses of elementary particles, also interacts with the world of the new physics that has been sought for decades. If this were indeed to be the case, the Higgs should decay in a characteristic way, involving exotic particles. At the Institute of Nuclear Physics of the Polish Academy of Sciences in Cracow, it has been shown that if such decays do indeed occur, they will be observable in successors to the LHC currently being designed.

When talking about the ‘hidden valley’, our first thoughts are of dragons rather than sound science. However, in high-energy physics, this picturesque name is given to certain models that extend the set of currently known elementary particles. In these so-called Hidden Valley models, the particles of our world as described by the Standard Model belong to the low-energy group, while exotic particles are hidden in the high-energy region. Theoretical considerations suggest then the exotic decay of the famous Higgs boson, something that has not been observed at the LHC accelerator despite many years of searching. However, scientists at the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow argue that Higgs decays into exotic particles should already be perfectly observable in accelerators that are successors to the Large Hadron Collider – if the Hidden Valley models turn out to be consistent with reality.

“In Hidden Valley models we have two groups of particles separated by an energy barrier. The theory is that there could then be exotic massive particles that could cross this barrier under specific circumstances. The particles like Higgs boson or hypothetic Z’ boson would act as communicators between the particles of both worlds. The Higgs boson, one of the most massive particle of the Standard Model, is a very good candidate for such a communicator,” explains Prof. Marcin Kucharczyk (IFJ PAN), lead author of an article in the Journal of High Energy Physics, which presents the latest analyses and simulations concerning the possibility of detecting Higgs boson decays in the future lepton accelerators.

New techniques can answer questions that were previously inaccessible experimentally — including questions about the relationship between quantum mechanics and relativity.

Scientists at TU Wien and other institutions have developed a “quantum simulator” using ultracold atomic clouds to model quantum particles in curved spacetime, marking a major step toward reconciling quantum theory and the theory of relativity. The model system offers a tool to study gravitational lensing effects in a quantum field, which may lead to new insights in the elusive field of quantum gravity and other areas of physics.

The theory of relativity works well when you want to explain cosmic-scale phenomena — such as the gravitational waves.

In a distant star system, a sunlike star orbits an invisible object that may be the first example of a ‘boson star’ made of dark matter, new research suggests.