Biomedical subjects

Fuminobu Takahashi

Publications and source records attributed to Fuminobu Takahashi.

2 recordsLinked to original sources

PubMed2006

Moduli-induced gravitino problem.

We investigate the cosmological moduli problem by studying a modulus decay in detail and find that the branching ratio of the gravitino production is generically of O(0.01-1), which causes another cosmological disaster. Consequently, the cosmological moduli problem cannot be solved simply by making the modulus mass heavier than 100 TeV. We also illustrate our results by explicitly calculating the branching ratio into the gravitinos in the mixed modulus-anomaly model.

Journal Article↗

PubMed2004

Baryogenesis in a flat direction with neither baryon nor lepton charge.

We present a new mechanism of spontaneous baryogenesis. Usually such mechanisms require a derivative coupling between a scalar field and baryon current. In our model, the scalar field instead derivatively couples to a current associated with some global symmetry U(1)(Q). In this case, baryogenesis is still possible provided that an interaction exists, which violates the baryon and U(1)(Q) symmetries simultaneously. As a concrete example, we discuss baryogenesis in a flat direction with neither baryon nor lepton charge.

Journal Article↗