Search results
Results from the WOW.Com Content Network
Main page; Contents; Current events; Random article; About Wikipedia; Contact us
Degenerate Higher-Order Scalar-Tensor theories (or DHOST theories) are theories of modified gravity.They have a Lagrangian containing second-order derivatives of a scalar field but do not generate ghosts (kinetic excitations with negative kinetic energy), because they only contain one propagating scalar mode (as well as the two usual tensor modes).
An important feature of loop quantum cosmology is the effective space-time description of the underlying quantum evolution. [10] The effective dynamics approach has been extensively used in loop quantum cosmology to describe physics at the Planck scale and the very early universe.
The Class VII (ages 11–12) book (Sindh Textbook Board) on Islamic Studies reads: "Most other religions of the world claim equality, but they never act on it." The Class VIII (ages 12–13) book (Punjab Textbook Board) on Islamic Studies reads: "Honesty for non-Muslims is merely a business strategy, while for Muslims it is a matter of faith."
Rules for how new elements are added are specified and, depending on the parameters in the model, different causal sets result. In analogy to the path integral formulation of quantum mechanics, one approach to developing a quantum dynamics for causal sets has been to apply an action principle in the sum-over-causal sets approach.
Unlike the standard cosmological model, the quasi steady state hypothesis implies the universe is eternal.According to Narlikar, multiple mini bangs would occur at the center of quasars, with various creation fields (or C-field) continuously generating matter out of empty space due to local concentration of negative energy that would also prevent violation of conservation laws, in order to ...
Extended theories of gravity are alternative theories of gravity developed from the starting points investigated first by Albert Einstein and Hilbert. These are theories describing gravity, which are metric theory , "a linear connection" or related affine theories, or metric-affine gravitation theory .
Both Brans–Dicke theory and general relativity are examples of a class of relativistic classical field theories of gravitation, called metric theories.In these theories, spacetime is equipped with a metric tensor, , and the gravitational field is represented (in whole or in part) by the Riemann curvature tensor, which is determined by the metric tensor.