Inflationary Cosmology
The research in inflationary cosmology represented below ranges from the original foundations of the theory — the first working examples, the first gauge invariant derivation of scale-invariant density fluctuations, the first complete computations of the scalar and tensor microwave background predictions — to exposing the flaws of the theory — the multiverse problem, the initial conditions problem, and the failed prediction of cosmic gravitational waves. The sequence of mounting problems ultimately motivated a new idea — bouncing universe.
A. Ijjas, A. Loeb, P.J. Steinhardt
POP! Goes the Universe Scientific American, January 2017
See also FAQs
Why inflationary cosmology is in more trouble than ever after Planck satellite 2015 results
P.J. Steinhardt
The Inflation Debate: is the theory at the heart of modern cosmology deeply flawed
Scientific American, March 2011
Inflationary cosmology is in trouble because of eternal inflation and quantum runaway leading to a multiverse of possible outcomes and no definite predictions
A. Ijjas, P.J. Steinhardt, A. Loeb
Classic versus Postmodern Inflation: Inflationary schism after Planck2013, Physics Letters B 736 (2014)142
More detailed critique of inflationary cosmology contrasting the original and current views of inflation
VIDEO: Series of short lectures at World Science U
BICEP2
INFLATION AND STRING THEORY
A. Bedroya, Q. Lu and P.J. Steinhardt
TCC in the interior of moduli space and its implications for the string landscape and cosmology
arXiv:2407.08793 (2024).
The case for the Transplanckian Censorship Conjecture (TCC) is strengthened, implying a new set of complex and highly nonlinear constraints across the entire string landscape which may make inflation impossible and restricts the ways dark energy can be incorporated in quantum gravity.
P. Agrawal, G. Obied, P.J. Steinhardt and C. Vafa
On the Cosmological Implications of the String Swampland
Phys.Lett. B784 (2018) p.271-6.
Inflation may not be compatible with string theory if the Swampland picture is correct
D. Wesley and P.J. Steinhardt
Dark Energy, Inflation and Extra Dimensions
Phys. Rev. D79 (2008) 104026.
and
Exploring extra dimensions through observational tests of dark energy and varying Newton’s constant, arXiv:1003.2815(2010)
Two papers exploring why cosmic acceleration (whether due to inflation or dark energy) is in tension with theories wth extra spatial dimeinsions.
D. Baumann, A. Dymarsky, I.R. Klebanov, L. McAllister, P.J. Steinhardt
A Delicate Universe, Phys. Rev. Lett. 99, 141601
Inflation model driven by D-branes reveals that extreme fine-tuning required
ARCHIVAL PAPERS
A. Albrecht, P. J. Steinhardt
Cosmology for grand unified theories with radiatively induced symmetry breaking, Phys. Rev. Lett. 48, (1982) 1220
First paper to introduce slow-roll inflation with Hubble damping
J. Bardeen, P.J. Steinhardt, M.S. Turner
Spontaneous creation of almost scale-free density perturbations in an inflationary universe
First paper to introduce the gauge invariant method of computating density perturbations in cosmology
P.J. Steinhardt
“Natural Inflation,” in The Very Early Universe, ed. by G. Gibbons, S. Hawking and S. Siklos, (Cambridge University Press: 1983), pp. 251
First paper to describe eternal inflation/multiverse (here called regenerative meta-cosmology
