919 research outputs found
A Radical Departure from the ''steady State'' Concept in Cosmology
Radical departure from steady state theory in cosmolog
On searches for gravitational waves from mini creation event by laser interferometric detectors
As an alternative view to the standard big bang cosmology the quasi-steady
state cosmology(QSSC) argues that the universe was not created in a single
great explosion; it neither had a beginning nor will it ever come to an end.
The creation of new matter in the universe is a regular feature occurring
through finite explosive events. Each creation event is called a mini-bang or,
a mini creation event(MCE). Gravitational waves are expected to be generated
due to any anisotropy present in this process of creation. Mini creation event
ejecting matter in two oppositely directed jets is thus a source of
gravitational waves which can in principle be detected by laser interferometric
detectors. In the present work we consider the gravitational waveforms
propagated by linear jets and then estimate the response of laser
interferometric detectors like LIGO and LISA
Mach's principle
The underlying idea in Mach's principle is that the origin of inertia or mass of a particle is a dynamical quantity determined by the environment, in particular the rest of the matter in the universe. In this article, we discuss the role of this idea in the Brans{Dicke theory of gravitation and the Hoyle Narlikar cosmology
Biscalar and bivector Green's functions in de Sitter space time
Biscalar and bivector Green's functions of wave equations are calculated explicitly in de Sitter space time. The calculation is performed by considering the electromagnetic field generated by the spontaneous creation of an electric charge
Time asymmetry in electrodynamics and cosmology
The concept of the 'arrow of time' is discussed in relation to thermodynamics, electrodynamics and cosmology Time symmetric electrodynamics, the absorber theory of radiation and quantum transitions receive attention to develop a working theory applicable to a universe with a perfect future absorber and an imperfect past absorber, such as the steady state cosmological model. It is stated that the approach adopted herein establishes a strong connection between the electrodynamic and cosmological arrows of time, and points a way towards linking these arrows with the thermodynamic one
Nonconservation of baryons in cosmology-revisited
The concept of the steady-state universe discussed by Hoyle & Narlikar two decades ago is revived in the light of the present discussions of the phase transition in the early big-bang universe. It is shown that with suitable scaling the bubble universe solution bears a striking similarity to the inflationary scenarios being discussed today. The currently discussed idea of cosmic baldness was also anticipated in the C-field cosmology of the steadystate universe
Hawking Radiation as a Mechanism for Inflation
The Friedman-Robertson-Walker (FRW) space-time exhibits particle creation
similar to Hawking radiation of a black hole. In this essay we show that this
FRW Hawking radiation leads to an effective negative pressure fluid which can
drive an inflationary period of exponential expansion in the early Universe.
Since the Hawking temperature of the FRW space-time decreases as the Universe
expands this mechanism naturally turns off and the inflationary stage
transitions to a power law expansion associated with an ordinary radiation
dominated Universe.Comment: 6 pages. Published version -- Awarded "Honorable Mention" for the
2012 Gravity Research Foundation Essay Contes
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