Nav: Home

Holographic cosmological model and thermodynamics on the horizon of the universe

March 26, 2020

Kanazawa, Japan - The expansion of the Universe has occupied the minds of astronomers and astrophysicists for decades. Among the cosmological models that have been suggested over the years, Lambda cold dark matter (LCDM) models are the simplest models that can provide elegant explanations of the properties of the Universe, e.g., the accelerated expansion of the late Universe and structural formations. However, the LCDM model suffers from several theoretical difficulties, such as the cosmological constant problem. To resolve these difficulties, alternative thermodynamic scenarios have recently been proposed that extend the concept of black hole thermodynamics.

"Previous research implies that a certain type of universe will behave like an ordinary macroscopic system. The expansion of the Universe is considered likely to be related to thermodynamics on its horizon, based on the holographic principle," explains the study's author, Kanazawa University's Nobuyoshi Komatsu.

"I considered a cosmological model with a power-law term, assuming application of the holographic equipartition law. The power-law term is proportional to Hα, where H is the Hubble parameter and α is considered to be a free parameter (α may be related to the entanglement of the quantum fields close to the horizon)."

"I used the proposed model to study the thermodynamic properties on the horizon of the Universe, focusing on the evolutions of the Bekenstein-Hawking entropy. I found that the model satisfies the second law of thermodynamics on the horizon," says Associate Professor Komatsu.

"In addition, I used the model to examine the relaxation-like processes that occur before the last stage of the evolution of the Universe and thus enable study of the maximization of the entropy."

"Figure 1 shows the boundaries for maximization of the entropy in the (α, ψ) plane. Here, ψ represents a type of density parameter for the effective dark energy. The upper side of each boundary corresponds to the region that satisfies the conditions for maximization of the entropy. For example, the point for the fine-tuned LCDM model is found to satisfy the conditions for maximization of the entropy at the present time. In addition, the region close to this point also satisfies the conditions for maximization of the entropy, both at the present time and in the future. Cosmological models in this region are likely to be favored from a thermodynamics viewpoint," says Associate Professor Komatsu.

In addition to the reported results of the study, it is hoped that the developed model will serve to enable discussion and analysis of the wide range of currently available cosmological models from a thermodynamics perspective.
-end-


Kanazawa University

Related Thermodynamics Articles:

Holographic cosmological model and thermodynamics on the horizon of the universe
A holographic cosmological model with a power-law term has been proposed by a Kanazawa University researcher to study thermodynamic properties on the horizon of the Universe.
APS tip sheet: Ultimate strength of metals
A new model is able to accurately determine the peak strength of polycrystalline metals.
How sensitive can a quantum detector be?
Measuring the energy of quantum states requires detecting energy changes so exceptionally small they are hard to pick out from background fluctuations, like using only a thermometer to try and work out if someone has blown out a candle in the room you're in.
A new model of metabolism draws from thermodynamics and 'omics'
Scientists at EPFL have developed an algorithm that can model biochemical reactions from metabolism down to RNA synthesis with unprecedented accuracy.
Samara Polytech scientists has developed a new concept of mathematical modeling
Scientists at the Samara Polytech are developing a new area of mathematical modeling of locally nonequilibrium transfer processes and methods for their study.
Theorem explains why quantities such as heat and power can fluctuate in microscopic system
Brazilian researchers participate in theoretical study that could have practical applications in nanoscale machine optimization.
Scientists recalculate the optimum binding energy for heterogeneous catalysis
In a discovery that could lead to the development of novel catalysts that do not rely on expensive rare metals, scientists from the RIKEN Center for Sustainable Resource Science have shown that the optimal binding energy can deviate from traditional calculations, which are based on equilibrium thermodynamics, at high reaction rates.
Team discovers polymorph selection during crystal growth can be thermodynamically driven
Lehigh University's Jeetain Mittal and his collaborators provide solid calculation to demonstrate the structural transformation in colloidal crystallization can be entirely thermodynamic, in contrast to the kinetic argument, from both theoretical and computational perspectives.
When kinetics and thermodynamics should play together
Research from the McKelvey School of Engineering suggests that without considering certain factors, researchers may overestimate how fast calcium carbonate forms in saline environments.
No assumptions needed to simulate petroleum reservoirs
New research published in EPJ E shows that if the right choices are made when constructing models of petroleum reservoirs, no guesswork is required to calculate the impact of their temperature gradients on their pressure and chemical gradients.
More Thermodynamics News and Thermodynamics Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Climate Mindset
In the past few months, human beings have come together to fight a global threat. This hour, TED speakers explore how our response can be the catalyst to fight another global crisis: climate change. Guests include political strategist Tom Rivett-Carnac, diplomat Christiana Figueres, climate justice activist Xiye Bastida, and writer, illustrator, and artist Oliver Jeffers.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Speedy Beet
There are few musical moments more well-worn than the first four notes of Beethoven's Fifth Symphony. But in this short, we find out that Beethoven might have made a last-ditch effort to keep his music from ever feeling familiar, to keep pushing his listeners to a kind of psychological limit. Big thanks to our Brooklyn Philharmonic musicians: Deborah Buck and Suzy Perelman on violin, Arash Amini on cello, and Ah Ling Neu on viola. And check out The First Four Notes, Matthew Guerrieri's book on Beethoven's Fifth. Support Radiolab today at Radiolab.org/donate.