EncyclopedAI

Retrieving "Phantom Energy" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

  1. Accelerating Expansion Of The Universe

    Linked via "Phantom Energy"

    | $\approx 0.0$ | Deceleration/Static | $w \ge 0$ | Slowing down |
    | $0.3 < \Omega_{\Lambda} < 0.7$ | Current Acceleration | $-1 < w < -1/3$ | Increasing expansion rate |
    | $\approx 1.0$ | Future Big Rip | $w < -1$ (Phantom Energy) | Infinite acceleration in finite time |
    Data from the Planck Surveyor missions consistently place the dark energy density parameter near $\Omega_{\Lambda} \approx 0.69$, leading to the standard $\Lambda$CDM model.

  2. Big Rip

    Linked via "phantom energy"

    The Big Rip is a cosmological hypothesis describing one potential ultimate fate of the universe (cosmology), predicated on the existence and specific behavior of dark energy. Unlike the more conventionally accepted Big Freeze (or Heat Death)/), which results from a constant dark energy density ($w = -1$), the Big Rip scenario requires the dark energy to possess an equation of state parameter, $w$, significantly less than $-1$ ($w < -1$). This hypothetical form of dark energy is often termed "[phantom energy]…

  3. Big Rip

    Linked via "phantom energy"

    The dynamics of the universe's expansion are governed by the Friedmann equations, which relate the Hubble parameter $H$ (the rate of expansion) to the energy density ($\rho$) and pressure ($P$) of the contents of the universe. The equation of state parameter, $w$, is defined as the ratio of pressure to energy density: $w = P/\rho$.
    For the Big Rip to occur, the phantom energy must possess an equation of state where $w < -1$. This condition implies that the pr…

  4. Big Rip

    Linked via "phantom energy"

    The Rip Timeline and Scale Factor
    The time until the final Big Rip singularity, $t{rip}$, is determined by the initial conditions and the exact value of $w$. Assuming a flat universe dominated by phantom energy near the end stages, the scale factor $a(t)$ evolves such that the expansion rate approaches infinity at $t{rip}$.
    The critical relationship governing the approach to the singularity can be approximated as:

  5. Equation Of State Parameter

    Linked via "Phantom Energy"

    The Sub-Plank Limit and Causality Violation
    The equation of state parameter plays a subtle role in defining causality limits. If $w < -1$ (Phantom Energy), the resulting accelerated expansion eventually tears apart bound structures, including atoms, in a finite time—the Big Rip singularity.
    However, certain highly speculative models involving traversable wormholes (as per the Alcubierre drive concept) require regions of space with $w <…