Variation of dust properties with cosmic time implied by radiative
  torque disruption
  Dust properties within a galaxy are known to change from the diffuse medium
to dense clouds due to increased local gas density. However, the question of
whether dust properties change with redshift remains elusive. In this paper,
using the fact that the mean radiation intensity of the interstellar medium
(ISM) of star-forming galaxies increases with redshift, we show that dust
properties should change due to increasing efficiency of rotational disruption
by radiative torques, an effect named RAdiative Torque Disruption (RATD). We
first show that, due to RATD, the size distribution of interstellar dust varies
with redshift, such as dust grains become smaller at higher $z$. We model the
extinction curves and find that the curve becomes steeper with increasing
redshift. The ratio of total-to-selective extinction, $R_{V}$, decreases with
redshift and achieves low values of $R_{V}\sim 1.5-2.5$ for grains having a
composite structure. We also find that dust properties change with the local
gas density due to RATD, but the change is dominated by the radiation field for
the diffuse ISM. The low values of $R_{V}$ implied by RATD of interstellar dust
could reproduce anomalous dust extinction observed toward type Ia supernovae
(SNe Ia) and Small Magellanic Cloud (SMC)-like extinction curves with a steep
far-UV rise toward high-z galaxies. Fluctuations in $R_{V}$ due to interstellar
turbulence and varying radiation intensity may resolve the tension in
measurements of the Hubble constant using SNe Ia. We finally discuss the
implications of evolving dust properties for high-z astrophysics.
