author={Hungsoo Kim and Gil Sang Lee and Yun Soo Myung},
  journal={Modern Physics Letters A},
We study how the noncommutative spacetime affects inflation. First we obtain the noncommutative power spectrum of the curvature perturbations produced during inflation in the slow-roll approximation. This is the explicit k-dependent power spectrum up to first order in slow-roll parameters e1, δ1 including the noncommutative parameter μ. In order to test the role of μ further, we calculate the noncommutative power spectrum using the slow-roll expansion. We find corrections which arise from the… 

Anisotropic constant-roll inflation with noncommutative model and swampland conjectures

In this paper, we study a constant-roll inflationary model in the presence of a noncommutative parameter with a homogeneous scalar field minimally coupled to gravity. The specific noncommutative

Generalized space-time noncommutative inflation

We study the noncommutative inflation with a time-dependent noncommutativity between space and time. From the numerical analysis of power law inflation, there are clues that the CMB spectrum

Can noncommutativity affect the whole history of the Universe

We study a classical, noncommutative (NC), Friedmann–Robertson–Walker (FRW) cosmological model. The spatial sections may have positive, negative or zero constant curvatures. The matter content is a

Noncommutative geometry and cosmology

We study some consequences of noncommutativity to homogeneous cosmologies by introducing a deformation of the commutation relation between the minisuperspace variables. The investigation is carried

Inflationary universe in deformed phase space scenario

Frame-dependence of higher-order inflationary observables in scalar-tensor theories

In the context of scalar-tensor theories of gravity we compute the third-order corrected spectral indices in the slow-roll approximation. The calculation is carried out by employing the Green's

Complete noncommutativity in a cosmological model with radiation

In order to try explaining the present accelerated expansion of the universe, we consider the most complete noncommutativity, of a certain type, in a Friedmann-Robertson-Walker cosmological model,

Is noncommutative eternal inflation possible?

We investigate the condition for eternal inflation to take place in the noncommutative spacetime. We find that the possibility for eternal inflation’s happening is greatly suppressed in this case. If

Strong Planck constraints on braneworld and non-commutative inflation

We place observational likelihood constraints on braneworld and non-commutative inflation for a number of inflaton potentials, using Planck, WMAP polarization and BAO data. Both braneworld and



Noncommutative spacetime, stringy spacetime uncertainty principle, and density fluctuations

We propose a variation of spacetime noncommutative field theory to realize the stringy spacetime uncertainty relation without breaking any of the global symmetries of the homogeneous isotropic

The Promise of string cosmology

The interplay between string theory and cosmology is very promising. Since string theory will yield a quantum theory of space-time and unify all forces of nature, it has the potential of addressing

Spectrum of density perturbations produced during inflation to leading order in a general slow-roll approximation

The standard calculation of the spectrum of density perturbations produced during inflation assumes (i) $|n\ensuremath{-}1|\ensuremath{\ll}1$ and (ii)

String theory.

The current “standard model” of particle physics—which is nearly 25 years old, has much experimental evidence in its favor and is comprised of six quarks, six leptons, four forces, and the as yet unobserved Higgs boson—contains internal indications that it, too, may be just another step along the path toward uncovering the truly fundamental degrees of freedom.

String theory

Abstract For each n > 0, two alternative axiomatizations of the theory of strings over n alphabetic characters are presented. One class of axiomatizations derives from Tarski's system of the

Phys. Rev. D

  • Phys. Rev. D
  • 2002


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