Ambjørn, Jan

Jan Ambjørn
The Niels Bohr Institute (NBI)
Copenhagen University
Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark

ArXiv: (The Universe from Scratch, (PDF),2005
A model for emergence of space and time, J. AmbjornY. Watabiki, 2015
Reconstructing the universe, 2005
Books: The Geometry of Dynamical Triangulations, Springer 1997
Google Scholar
Homepage (NBI): DBpedia (About) Radboud (RU), Worldcat
YouTube: With Wolfram, August 2021

Most recent email: 13 July 2021 at 12:23 PM

Dear Prof. Dr. Jan Ambjørn:

Thank you for your work to develop Causal Dynamical Triangulations (CDT)
where Wikipedia cites you as the prime mover for its development.

The Planck scale is difficult for most of us.
1. Did Max do a reasonable job defining the base units?
John Ralston (Kansas) believes Planck’s Constant throws it all off.
Reference: Quantum Theory without Planck’s Constant, (PDF), Mar 2012
2. Do the Planck base units define (or metaphorically define) the first instant of the universe?


First email: November 19, 2016, 10:20 PM (lightly updated)

The Universe from Scratch, 2005. 
The Geometry of Dynamical Triangulations (Springer 1997)
ArXiv (113)
A model for emergence of space and time, 2015

Dear Professor Jan Ambjørn:

Thank you for all your work.  Very, very helpful. I first found you within ArXiv.  Though well along in years (69 years old), you have embraced topics which I find most fascinating.  So, you have a new  student (de facto)!

I will attempt to digest your writings to give me insight in order to write a sequel to my post yesterday: “Simple Math-Geometry-And-Logic Render A Simple Model Of The Universe” or

Of course, I would be honored with even your cursory look and comments.

Most sincerely,


Institute for Theoretical Physics, Utrecht University,  Minnaert Building,
Leuvenlaan 4, NL-3584 CE Utrecht, The Netherlands