A Generalization of Gauge Symmetry, Fourth-Order Gauge Field Equations
  and Accelerated Cosmic-Expansion
  A generalization of the usual gauge symmetry leads to fourth-order gauge
field equations, which imply a new constant force independent of distances. The
force associated with the new $U_1$ gauge symmetry is repulsive among baryons.
Such a constant force based on baryon charge conservation gives a
field-theoretic understanding of the accelerated cosmic-expansion in the
observable portion of the universe dominated by baryon galaxies. In consistent
with all conservation laws and known forces, a simple rotating `dumbbell model'
of the universe is briefly discussed.
