Nav: Home

Beyond Einstein

December 20, 2018

When stars collapse, they can create black holes, which are everywhere throughout the universe and therefore important to be studied. Black holes are mysterious objects with an outer edge called an event horizon, which traps everything including light. Einstein's theory of general relativity predicted that once an object falls inside an event horizon, it ends up at the center of the black hole called a singularity where it is completely crushed. At this point of singularity, gravitational attraction is infinite and all known laws of physics break down including Einstein's theory. Theoretical physicists have been questioning if singularities really exist through complex mathematical equations over the past several decades with little success until now. LSU Department of Physics & Astronomy Associate Professor Parampreet Singh and collaborators LSU Postdoctoral Researcher Javier Olmedo and Abhay Ashtekar, the Eberly Professor of Physics at Penn State developed new mathematical equations that go beyond Einstein's theory of general relativity overcoming its key limitation--the central singularity of black holes. This research was published recently in Physical Review Letters and Physical Review D and was highlighted by the editors of the American Physical Society.

Theoretical physicists developed a theory called loop quantum gravity in the 1990s that marries the laws of microscopic physics, or quantum mechanics, with gravity, which explains the dynamics of space and time. Ashtekar, Olmedos and Singh's new equations describe black holes in loop quantum gravity and showed that black hole singularity does not exist.

"In Einstein's theory, space-time is a fabric that can be divided as small as we want. This is essentially the cause of the singularity where the gravitational field becomes infinite. In loop quantum gravity, the fabric of space-time has a tile-like structure, which cannot be divided beyond the smallest tile. My colleagues and I have shown that this is the case inside black holes and therefore there is no singularity," Singh said.

Instead of singularity, loop quantum gravity predicts a funnel to another branch of the space-time.

"These tile-like units of geometry--called 'quantum excitations'-- which resolve the singularity problem are orders of magnitude smaller than we can detect with today's technology, but we have precise mathematical equations that predict their behavior," said Ashtekar, who is one of the founding fathers of loop quantum gravity.

"At LSU, we have been developing state-of-the-art computational techniques to extract physical consequences of these physical equations using supercomputers, bringing us closer to reliably test quantum gravity," Singh said.

Einstein's theory fails not only at the center of the black holes but also to explain how the universe was created from the Big Bang singularity. Therefore, a decade ago, Ashtekar, Singh and collaborators began to extend physics beyond the Big Bang and make new predictions using loop quantum gravity. Using the mathematical equations and computational techniques of loop quantum gravity, they showed that the Big Bang is replaced by the "Big Bounce." But, the problem of overcoming black hole singularity is exceptionally complex.

"The fate of black holes in a quantum theory of gravity is, in my view, the most important problem in theoretical physics," said Jorge Pullin, the Horace Hearne professor of theoretical physics at LSU, who was not part of this study.
-end-
The research was supported by the U.S. National Science Foundation, the Urania Stott Fund of the Pittsburgh Foundation, the Penn State Eberly College of Science and the Ministry of Economy and Competitiveness, or MINECO, in Spain.

Louisiana State University

Related Black Holes Articles:

Supermassive black holes found in 2 tiny galaxies
U astronomers and colleagues have found two ultra-compact dwarf galaxies with supermassive black holes, the second and third such galaxies found to harbor the objects.
Stars born in winds from supermassive black holes
Observations using ESO's Very Large Telescope have revealed stars forming within powerful outflows of material blasted out from supermassive black holes at the cores of galaxies.
Did LIGO detect black holes or gravastars?
After the first direct detection of gravitational waves that was announced last February by the LIGO Scientific Collaboration and made news all over the world, Luciano Rezzolla (Goethe University Frankfurt, Germany) and Cecilia Chirenti (Federal University of ABC in Santo André, Brazil) set out to test whether the observed signal could have been a gravastar or not.
New research reveals hundreds of undiscovered black holes
Computer simulations of a spherical collection of stars known as 'NGC 6101' reveal that it contains hundreds of black holes, until now thought impossible.
Chorus of black holes radiates X-rays
The NuSTAR mission is identifying which black holes erupt with the highest-energy X-rays.
Did the LIGO gravitational waves originate from primordial black holes?
Binary black holes recently discovered by the LIGO-Virgo collaboration could be primordial entities that formed just after the Big Bang, report Japanese astrophysicists.
A new look at the galaxy-shaping power of black holes
Data from a now-defunct satellite is providing new insights into the complex tug-of-war between galaxies, the hot plasma that surrounds them, and the giant black holes that lurk in their centers.
The energy spectrum of particles will help make out black holes
Scientists from MIPT, the Institute for Theoretical and Experimental Physics, and the National Research University Higher School of Economics have devised a method of distinguishing black holes from compact massive objects that are externally indistinguishable from one another.
Using gravitational waves to catch runaway black holes
Black holes are the most powerful gravitational force in the universe.
Black holes and measuring gravitational waves
The supermassive black holes found at the center of every galaxy, including our own Milky Way, may, on average, be smaller than we thought, according to work led by University of Southampton astronomer Dr.

Related Black Holes Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#529 Do You Really Want to Find Out Who's Your Daddy?
At least some of you by now have probably spit into a tube and mailed it off to find out who your closest relatives are, where you might be from, and what terrible diseases might await you. But what exactly did you find out? And what did you give away? In this live panel at Awesome Con we bring in science writer Tina Saey to talk about all her DNA testing, and bioethicist Debra Mathews, to determine whether Tina should have done it at all. Related links: What FamilyTreeDNA sharing genetic data with police means for you Crime solvers embraced...