  We report the results of photometry of the WZ Sge-type dwarf nova V455 And.
Observations were obtained over 19 nights in 2013 and 2014. The total duration
of the observations was 96 h. We clearly detected three coherent oscillations
with periods of 80.376+/-0.003 min, 40.5431+/-0.0004 min and
67.619685+/-0.000040 s. The 67.619685-s period can be the spin period of the
white dwarf. The 40.5431-minute period is the first harmonic of the orbital
period. The 80.376-minute oscillation can be a negative superhump because its
period is 0.9% less than the orbital period. This oscillation was evident both
in the data of 2013 and in the data of 2014. These results make V455 And a
permanent superhump system which shows negative superhumps. This is also the
first detection of persistent negative superhumps in a WZ Sge-type dwarf nova.
In addition, the analysis of our data revealed incoherent oscillations with
periods in the range 5-6 min, which were observed earlier and accounted for by
non-radial pulsations of the white dwarf. Moreover, we clearly detected an
oscillation with a period of 67.28+/-0.03 s, which was of a low degree of
coherence. This oscillation conforms to the beat between the spin period of the
white dwarf and the 3.5-h spectroscopic period, which was discovered earlier
and accounted for by the free precession of the white dwarf. Because the
67.28-s period is shorter than the spin period and because the free precession
of the white dwarf is retrograde, we account for the 67.28-s oscillation by the
free precession of the white dwarf.
