The phrase "a regular matter of" is correct and usable in written English.
It can be used to describe something that occurs frequently or is a common occurrence in a particular context.
Example: "In our department, communication is a regular matter of concern that we address in every meeting."
Alternatives: "a common issue of" or "a frequent topic of".
But very occasionally one will bump into a piece of "regular" matter - and that is what they are hoping to detect with DarkSide50.
The red part and the blue part of the picture thus represent two very different kinds of matter: regular matter seen through its emission of detectable x-rays, and dark matter, seen only through the fact that it acts gravitationally on light from a source that is behind this cluster.
As these celestial systems rotate around their dense centre, all of the regular matter that they contain does not have enough mass to account for the gravity needed to hold everything together.
Results from the WMAP team in 2008 are in accordance with a universe that consists of 73% dark energy, 23% dark matter, 4.6% regular matter and less than 1% neutrinos.
Make regular exercise a matter of routine.
Ramirez was back playing in the regular season within a matter of a couple of weeks.
There was a time when weather of the kind Britain is experiencing now – a much more regular occurrence – was a matter of life and death.
But instead of hearty young Frenchmen awaiting our charms, that morning there was a fat, elderly dog and a few men of similar description — regulars having a crème or (equally a matter of course) wine or a pastis.
The fact that there is low awareness of safety measures and low frequency of their regular utilisation is a matter of concern.
Racist incidents were a daily occurrence there, not from the staff or management, but his co-habitants – matters compounded by a regular diet of abuse in public, he adds.
