  According to the Cold Dark Matter (CDM) hierarchical clustering theory of
galaxy and large scale structure formation, there should be numerous low mass
dark matter haloes present in the Universe today. If these haloes contain
sufficient stars they should be detectable as low luminosity stellar systems or
dwarf galaxies. We have previously described a new detection method for faint
low surface brightness objects and shown that there are relatively large
numbers of very faint dwarf galaxies in the nearby Virgo cluster. In this paper
we present results from a similar survey carried out on the Millennium Galaxy
strip which runs along the celestial equator and samples a very different
galaxy environment. We show that the dwarf-to-giant galaxy number ratio along
this strip ranges from 0.7:1 to, at most, 6:1, corresponding to a flat
luminosity function (alpha approx -0.8 to -1.0). This is very different to our
value of 20:1 for the Virgo cluster. There is no population of low surface
brightness dwarf galaxies in the field that have gone undetected by the
redshift surveys. This result is exactly opposite to what CDM models predict
for the environmental dependence of the dark matter mass function which is that
there are proportionally more small dark matter haloes in lower density
environments.
