Gravitino Condensation and Cosmological Inflation

首都大学東

Pole inflation and primordial black holes formation in Starobinsky-like supergravity

We extend the Cecotti-Kallosh model of Starobinsky inflation in supergravity by adding a holomorphic function to the superpotential in order to generate a large peak in the power spectrum of scalar (curvature) perturbations. In our approach, the singular non-canonical kinetic terms are largely responsible for inflation (as an attractor solution), whereas the superpotential is engineered to generate a production of primordial black holes. We study the cases with (i) a linear holomorphic function, (ii) a quadratic holomorphic function, and (iii) an exponential holomorphic function, as regards the dependence of inflation and primordial black holes production upon parameters of those functions and initial conditions, as well as verify viability of inflation with our superpotentials. We find that an efficient production of primordial black holes consistent with CMB measurements is only possible in the second (ii) case. We calculate the masses of the produced primordial black holes and find that they are below the Hawking (black hole) evaporation limit, so that they cannot be part of the current dark matter in our Universe.Comment: 22 pages, 16 figures, LaTeX; short comments added, figures update

Gravitino condensate in N = 1 supergravity coupled to the N = 1 supersymmetric Born–Infeld theory

The $N=1$ supersymmetric Born-Infeld theory coupled to $N=1$ supergravity in four spacetime dimensions is studied in the presence of a cosmological term with spontaneous supersymmetry breaking. The consistency is achieved by compensating a negative contribution to the cosmological term from the Born-Infeld theory by a positive contribution originating from the gravitino condensate. This leads to an identification of the Born-Infeld scale with the supersymmetry breaking scale. The dynamical formation of the gravitino condensate in supergravity is reconsidered and the induced one-loop effective potential is derived. Slow roll cosmological inflation with the gravitino condensate as the inflaton (near the maximum of the effective potential) is viable against the Planck 2018 data and can lead to the inflationary (Hubble) scale as high as $10^{12}$ GeV. Uplifting the Minkowski vacuum (after inflation) to a de Sitter vacuum (dark energy) is possible by the use of the alternative Fayet-Iliopoulos term. Some major physical consequences of our scenario to reheating are briefly discussed also.Comment: 15 pages, 2 figures, LaTeX; section 2 revised, main results unchanged; comments added; misprints correcte

Beyond Starobinsky inflation

A supergravity extension of the (R+R2) gravity with the additional (Born-Infeld) structure of a massive vector multiplet gives rise to the specific F(R) gravity, whose structure is investigated in detail. The massive vector multiplet has an inflaton (scalaron), goldstino, and massive vector field as its field components. The model describes Starobinsky inflation and allows us to extrapolate the F(R) function beyond the inflationary scale (up to Planck scale). We observe some differences versus the (R+R2)gravity and several breaking patterns of the well-known correspondence between the F(R) gravity and the scalar-tensor gravity

Assessment of bacillus subtilis plasmid pls20 conjugation in the absence of quorum sensing repression

Bacillus subtilis conjugative plasmid pLS20 uses a quorum-sensing mechanism to control expression levels of its conjugation genes, involving the repressor RcopLS20, the anti-repressor Rap-pLS20, and the signaling peptide Phr*pLS20. In previous studies, artificial overexpression of rappLS20 in the donor cells was shown to enhance conjugation efficiency. However, we found that the overex-pression of rappLS20 led to various phenotypic traits, including cell aggregation and death, which might have affected the correct determination of the conjugation efficiency when determined by colony formation assay. In the current study, conjugation efficiencies were determined under different conditions using a two-color fluorescence-activated flow cytometry method and measuring a single-round of pLS20-mediated transfer of a mobilizable plasmid. Under standard conditions, the conjugation efficiency obtained by fluorescence-activated flow cytometry was 23-fold higher than that obtained by colony formation. Furthermore, the efficiency difference increased to 45-fold when rappLS20 was overexpressed.Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Scientific Research 18H02128 to K.-i.Y., Bilateral Joint Research Projects/Seminars of JSPS and the Royal Society to K.-i.Y. and A.W., and by grant [PID2019 108778GB C21 (AEI/FEDER, EU)] of the ministry of Science and Innovation of the Spanish Governmen