Beginning inflation in an inhomogeneous universe
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)
- Center for Cosmology and Particle Physics, New York University, New York, New York 10003 (United States)
- SITP and Department of Physics, Stanford University,Stanford, California 94305 (United States)
Using numerical solutions of the full Einstein field equations coupled to a scalar inflaton field in 3+1 dimensions, we study the conditions under which a universe that is initially expanding, highly inhomogeneous and dominated by gradient energy can transition to an inflationary period. If the initial scalar field variations are contained within a sufficiently flat region of the inflaton potential, and the universe is spatially flat or open on average, inflation will occur following the dilution of the gradient and kinetic energy due to expansion. This is the case even when the scale of the inhomogeneities is comparable to the initial Hubble length, and overdense regions collapse and form black holes, because underdense regions continue expanding, allowing inflation to eventually begin. This establishes that inflation can arise from highly inhomogeneous initial conditions and solve the horizon and flatness problems, at least as long as the variations in the scalar field do not include values that exceed the inflationary plateau.
- Sponsoring Organization:
- SCOAP3, CERN, Geneva (Switzerland)
- OSTI ID:
- 22572146
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2016, Issue 09; Other Information: PUBLISHER-ID: JCAP09(2016)010; OAI: oai:repo.scoap3.org:17061; cc-by Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COSMOLOGY AND ASTRONOMY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BLACK HOLES
COSMOLOGICAL INFLATION
EINSTEIN FIELD EQUATIONS
FOUR-DIMENSIONAL CALCULATIONS
GRAVITATIONAL COLLAPSE
INFLATIONARY UNIVERSE
INFLATONS
KINETIC ENERGY
NUMERICAL SOLUTION
SCALAR FIELDS
UNIVERSE
VARIATIONS