This is a theory presented by mathematician Brian Whitworth ; PDF that suggests we are living in an information system known as a Virtual Reality.
The PDF is a 16 page publication that I introduce first as it’s short; to the point theory makes for an easy read to begin the discussion on this theory. The concept that we are existing in a virtual reality is not just Brain Whitworths summation alone, several other physicists; philosophers and scientists have proposed this hypothesis.
Physicist Tom Campbell  who worked for the DoD and Nasa published a trilogy of his accumulated knowledge in consciousness exploration stemming from and beyond his work at the Monroe Institute  setting up the laboratory and controls to explore a state known as mind awake / body asleep which is associated to being awake in conscious space when your body is asleep. Other terms for this are commonly known as lucid dream; conscious dreaming and out-of-body experiences.
Tom takes the concept of Virtual Reality into a full 820 page trilogy called “My Big Toe” which can be read on Google Books PDF and expands the concept into many Universes including a non-physical reality system which supersedes physical reality exponentially; the concept of “The Big Computer” and several analogies into concepts such as “Process Fractals” which are iterations used by TBC to evolve reality. His view also supports an evolving Universe; rather then one that has already evolved.
A Russian scientist named Sergey Datsyuk  has a publication called, “The Theory of Virtuality” which is a patient paste into google translate as it is completely written in Russian; HTML
Another virtual reality theory is known as “Multiverse Theory”. Multiverse Theory’ Holds That the Universe is a Virtual Reality Matrix.
“We may be a simulation … creations of some supreme, or super-being,” muses Britain’s astronomer royal, Sir Martin Rees, a staunch advocate of the multiverse theory. 
This theory is stoutly supported in a publication entitled: “ARE YOU LIVING IN A COMPUTER SIMULATION?”  BY NICK BOSTROM, Department of Philosophy, Oxford University HTML
Our Virtual Reality Universe Written by Ian O’Neill Universe Today HTML  reflects on Brian Whitworths hypothesis;
If we were living in a Virtual Reality; how would we know? If this is in fact some artificial reality created by a technology; who created it; what is the technology composed of and how to we test this theory?
Perhaps Craig Hogan’s theory that the Universe is a giant Hologram  HTML which gained attention when the GEO600 gravitational wave detector detected a fuzziness predicted by Hogan which implicates system found in holograms; helps reveal pixels in this virtual reality.
We have the theories; we have some plausibility in our current technology that may be in fact detecting the pixel by which the virtual reality is rendered. If this theory proves to be true; it will change everything we know about reality and information systems.
YAD.[References] The Physical World as a Virtual Reality by Brian Whitworth src
 “My Big Toe” by Tom Campbell src
 The Monroe Institute src
 The Theory of Virtuality by Sergey Datsyuk src
 Multiverse Theory’ Holds That the Universe is a Virtual Reality Matrix Sydney Morning Herald | July 22 2004 src
 “ARE YOU LIVING IN A COMPUTER SIMULATION?” BY NICK BOSTROM, Department of Philosophy, Oxford University src
 Our Virtual Reality Universe Written by Ian O’Neill Universe Today src
 Our world may be a giant hologram 15 January 2009 by Marcus Chown src