Physics bcrec

https://www.facebook.com/reel/338483589190578

The largest X-ray map of the universe is here!

New research suggests that our universe has no dark matter

The current theoretical model for the composition of the universe is that it’s made of normal matter, dark energy and dark matter. A new University of Ottawa study challenges this.

A study, published in The Astrophysical Journal, challenges the current model of the universe by showing that, in fact, it has no room for dark matter.

In cosmology, the term “dark matter” describes all that appears not to interact with light or the electromagnetic field, or that can only be explained through gravitational force. We can’t see it, nor do we know what it’s made of, but it helps us understand how galaxies, planets and stars behave.

Rajendra Gupta, a physics professor at the Faculty of Science, used a combination of the covarying coupling constants (CCC) and “tired light” (TL) theories (the CCC+TL model) to reach this conclusion.

This model combines two ideas—about how the forces of nature decrease over cosmic time and about light losing energy when it travels a long distance. It’s been tested and has been shown to match up with several observations, such as about how galaxies are spread out and how light from the early universe has evolved.

This discovery challenges the prevailing understanding of the universe, which suggests that roughly 27% of it is composed of dark matter and less than 5% of ordinary matter, remaining being the dark energy.

Challenging the need for dark matter in the universe
“The study’s findings confirm that our previous work (“JWST early universe observations and ΛCDM cosmology“) about the age of the universe being 26.7 billion years has allowed us to discover that the universe does not require dark matter to exist,” explains Gupta.

“In standard cosmology, the accelerated expansion of the universe is said to be caused by dark energy but is in fact due to the weakening forces of nature as it expands, not due to dark energy.”

Dark matter makes up most of the mass of galaxies and galaxy clusters, and is responsible for the way galaxies are organized on grand scales. Dark energy, meanwhile, is the name we give the mysterious influence driving the accelerated expansion of the universe.
All the atoms and light in the universe together make up less than five percent of the total contents of the cosmos. The rest is composed of dark matter and dark energy, which are invisible but dominate the structure and evolution of the universe. Dark matter makes up most of the mass of galaxies and galaxy clusters, and is responsible for the way galaxies are organized on grand scales. Dark energy, meanwhile, is the name we give the mysterious influence driving the accelerated expansion of the universe. What these substances are and how they work are some of the major challenges facing modern astronomers.
Write about Dark matter and Dark Energy.

Low Resistance Ohomic Contact to p-CdTe thin film and Metal:

This brief contains an investigation on the method for obtaining a stable low resistance ohmic contact to p-CdTe thin film. The contact was obtained by introducing a thin CuxO (0 < x ≤ 1) layer in between the metal and CdTe. The oxide layer mediated the contact by a charge polarization effect. The specific contact resistances between metal-CdTe were analyzed with and without a CuxO layer. It has been observed that contacts mediated by charge polarization effects offer comparably low resistance and better stability than the contacts obtained by the dopant-induced surface fields. The new type of contacts employ polarization of charges to enhance a tunneling transport mechanism. The contacts have linear current-voltage (I-V) characteristics with a contact resistance of 2.2 × 10-2 Ω-cm2, as obtained from linear TLM measurements.