"I think first it was the deceleration parameter," said Shoe.

The second number, known as the deceleration parameter, indicated how much the cosmos had been warped by the density of its contents.

The deceleration parameter measurements are right.

"I would understand better if I knew what a deceleration parameter was," Audee groaned.

"Yes, the deceleration parameter.

The minus sign and name "deceleration parameter" are historical; at the time of definition was thought to be positive, now it is believed to be negative.

The derivative of the Hubble parameter can be written in terms of the deceleration parameter:

This had suggested that the deceleration parameter was equal to one half; the experimental effort to confirm this prediction led to the discovery of possible acceleration.

Except in the speculative case of phantom energy (which violates all the energy conditions), all postulated forms of matter yield a deceleration parameter .

The expansion of the universe is said to be "accelerating" if is positive (recent measurements suggest it is), and in this case the deceleration parameter will be negative.

The deceleration parameter in cosmology is a dimensionless measure of the cosmic acceleration of the expansion of space in a Friedmann-Lemaître-Robertson-Walker universe.

Surprisingly, the deceleration parameter was measured by two different groups to be less than zero (actually, consistent with -1) which implied that today Hubble's Constant is increasing as time goes on.

Yun-Gui Gong and Anzhong Wang, Reconstruction of the deceleration parameter and the equation of state of dark energy, Phys.

Inflation is often called a period of accelerated expansion because the distance between two fixed observers is increasing exponentially (i.e. at an accelerating rate as they move apart), while can stay approximately constant (see deceleration parameter).

Scientists have collected observational evidences for the accelerated state of the present universe, wherefore is held that the deceleration parameter was positive in the early phases of the matter dominated era, but became negative during the later stages.

This work led to the precise measurements of the Hubble Constant H and the deceleration parameter q, the latter indicating the presence of a dark energy or cosmological constant dominating the mass/energy of the Universe.

In 1994, Schmidt and Nicholas B. Suntzeff formed the High-Z Supernova Search Team to measure the expected deceleration of the Universe and the deceleration parameter q0 using distances to Type Ia supernovae.

The missile fell about fifty feet as its gyroscope stabilization system steadied the fifteen-hundred-pound missile; then, when the air data probes detected the proper airflow and deceleration parameters indicating a clean release from the Black Knight bomber, the powerful turbojet engine kicked in.

This relationship has allowed the use of Type Ia supernovae as standard candles, leading to the precise measurements of the Hubble constant H and the deceleration parameter q, the latter implying the existence of dark energy or a cosmological constant in the Universe.

It was expected that the Hubble Constant would be decreasing as time went on due to the influence of gravitational interactions in the universe, and thus there is an additional observable quantity in the universe called the deceleration parameter which cosmologists expected to be directly related to the matter density of the universe.