enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Cyclic model - Wikipedia

    en.wikipedia.org/wiki/Cyclic_model

    A cyclic model (or oscillating model) is any of several cosmological models in which the universe follows infinite, or indefinite, self-sustaining cycles. For example, the oscillating universe theory briefly considered by Albert Einstein in 1930 theorized a universe following an eternal series of oscillations, each beginning with a Big Bang and ending with a Big Crunch; in the interim, the ...

  3. Decomposition of time series - Wikipedia

    en.wikipedia.org/wiki/Decomposition_of_time_series

    An additive model would be used when the variations around the trend do not vary with the level of the time series whereas a multiplicative model would be appropriate if the trend is proportional to the level of the time series. [3] Sometimes the trend and cyclical components are grouped into one, called the trend-cycle component.

  4. Cyclostationary process - Wikipedia

    en.wikipedia.org/wiki/Cyclostationary_process

    For time series, the reason the cyclic spectral density function is called the spectral correlation density function is that it equals the limit, as filter bandwidth approaches zero, of the average over all time of the product of the output of a one-sided bandpass filter with center frequency + / and the conjugate of the output of another one ...

  5. Time series - Wikipedia

    en.wikipedia.org/wiki/Time_series

    Time series: random data plus trend, with best-fit line and different applied filters. In mathematics, a time series is a series of data points indexed (or listed or graphed) in time order. Most commonly, a time series is a sequence taken at successive equally spaced points in time.

  6. List of cycles - Wikipedia

    en.wikipedia.org/wiki/List_of_cycles

    Animal migration – Avalanche – Carbon cycle – Climate change – Climate change and agriculture – Climate model – Climate oscillation – Clock of the Long Now – Ecology – El Niño/La Niña – Endometrium – Environmental geography – Global cooling – Global warming – Historical temperature record – Hydrogen cycle – Ice age – Transhumance – Milankovitch cycles ...

  7. Conformal cyclic cosmology - Wikipedia

    en.wikipedia.org/wiki/Conformal_cyclic_cosmology

    Conformal cyclic cosmology (CCC) is a cosmological model in the framework of general relativity and proposed by theoretical physicist Roger Penrose. [1] [2] [3] In CCC, the universe iterates through infinite cycles, with the future timelike infinity (i.e. the latest end of any possible timescale evaluated for any point in space) of each previous iteration being identified with the Big Bang ...

  8. Hodrick–Prescott filter - Wikipedia

    en.wikipedia.org/wiki/Hodrick–Prescott_filter

    A working paper by Robert J. Hodrick titled "An Exploration of Trend-Cycle Decomposition Methodologies in Simulated Data" [10] examines whether the proposed alternative approach of James D. Hamilton is actually better than the HP filter at extracting the cyclical component of several simulated time series calibrated to approximate U.S. real GDP ...

  9. Cycles of Time - Wikipedia

    en.wikipedia.org/wiki/Cycles_of_Time

    Cycles of Time: An Extraordinary New View of the Universe is a science book by mathematical physicist Roger Penrose published by The Bodley Head in 2010. The book outlines Penrose's Conformal Cyclic Cosmology (CCC) model, which is an extension of general relativity but opposed to the widely supported multidimensional string theories and cosmological inflation following the Big Bang.