In cosmology, the equation of state of a perfect fluid is characterized by a dimensionless number , equal to the ratio of its pressure to its energy density: . It is closely related to the …

Dec 24, 2022 · In this paper we will study the Equation of state in cosmology. Stable w of the state equation is the ratio of the pressure exerted by dark energy on the universe to the energy per...

Nov 21, 2014 · In this paper, we demonstrate that the equation of state in R_h=ct helps us to understand why the optimized fraction Omega_m=rho_m/rho in LCDM must be ~0.27, an …

There are three di erent forms of matter and energy in our universe and they all satisfy the relation p(t) = w (t), where the constant w is called the equation of state parameter. Plugging this into …

First, the mass density ρ(t) is replaced by the total energy density (t)/c2, which includes rest mass energy and other forms of energy (e.g., energy of photons, or thermal energy of atoms). [In …

Introducing matter into a steady-state universe violates energy conservation, since matter does not have the p = - c 2 equation of state that allows the density to remain constant. This is the …

The equation of state gives pressure P in terms of ρ. P = wρc2 where w = 0 for matter, w = 1/3 for radiation, and w = −1 for dark energy. 1

Each component has its own equation of state parameter, wi: w = 0 for non-relativistic matter (baryons, CDM); w = 1/3 for radiation or other relativistic fluid; w = -1 for a cosmological …

Mar 24, 2025 · This paper reports improvements and new results for a well developed theory of tachyons (faster-than-light particles) and follows the suggestion that neutrinos - especially the …

Sep 23, 2003 · Determining the first three Taylor coefficients of the equation of state at the current epoch requires a measurement of the deceleration, jerk, and snap -- the second, third, and …

cosmic equation of state, relating the total energy den-sity ρ to its total pressure p. In principle, if we knew these quantities precisely, we could then solve the dynamical equations governing …

Our Goal here is to derive the equation of state (or the mutual dependencies among local thermodynamic quantities such as P, T, ρ, and Ni), not only for the classic ideal gas, but also …

Dec 4, 2014 · In this paper, we explore this hypothesis quantitatively and demonstrate that the equation-of-state in R h = ct helps us to understand why the optimized fraction Ω m ≡ ρ m / ρ …

The Equation of State • Defines the dependence of the density vs. volume for a given matter/energy component, to enter in the Friedman eq. • Usually written as p = w • This is not …

In this paper, we explore this hypothesis quantitatively and demonstrate that the equation-of-state in R h = ct helps us to understand why the optimized fraction Ω m ≡ ρ m / ρ in ΛCDM today …

In cosmology, the equation of state of a perfect fluid is characterized by a dimensionless number , equal to the ratio of its pressure to its energy density: . It is closely related to the …

An effective equation of state parameter for the cosmic fluid of radiation, matter and dark energy of the form: !eff = [1 + (z=( R)) d]=3, where z is a constant is shown a beautiful expression for …

In cosmology, the equation of state of a perfect fluid is characterized by a dimensionless number , equal to the ratio of its pressure to its energy density: It is closely related to the thermodynamic …

The equation of state parameter, often denoted as $w$, is a dimensionless quantity that describes the relationship between pressure and density in a given cosmic fluid. Specifically, it is defined …

4 days ago · One of the central challenges in modern cosmology is understanding the nature of dark energy and its evolution throughout the history of the Universe. Dark energy is commonly …

Understanding the equation of state is essential for predicting phenomena such as supernova explosions, the formation of neutron stars, and the overall dynamics of cosmic structures. How …

Nov 21, 2014 · In this paper, we demonstrate that the equation of state in R_h=ct helps us to understand why the optimized fraction Omega_m=rho_m/rho in LCDM must be ~0.27, an …

Mar 24, 2025 · You may have already guessed from the name, but DESI is primarily meant to study dark energy—as part of the team puts it, “DESI aims to place unprecedented constraints …

Mar 7, 2025 · The method uses measurements of the mass and radius of a neutron star to determine the equation of state of the matter in its core—how soft or stiff the matter is. These …

Feb 27, 2025 · More information: Ryan Abbott et al, QCD Constraints on Isospin-Dense Matter and the Nuclear Equation of State, Physical Review Letters (2025). DOI: …

Hugh Everett III's relative-state formulation of quantum mechanics is an attempt to solve the quantum measurement problem by dropping the collapse dynamics from the standard von …