# :: Michael Flohr ::

# :: Home Page ::

This is the home page of Michael Flohr. The links on the left side
give you access to resources and information concerning almost
entirely my scientific work as a mathematical physicist. If you
desire to learn more about me, you find here the current version of
my
Curriculum Vitæ
[‑‑> english :: ‑‑> german]
in pdf format.
If you wish to get into touch with me in a way which protects privacy,
use my public
‑‑> gpg key.

### :: Contact Details ::

Priv.-Doz. Dr. Michael FlohrInstitute for Theoretical Physics Gottfried Wilhelm Leibniz University Hannover Appelstraße 2 D-30167 Hannover, Germany Phone :: +49 511 762-3656 Fax :: +49 511 762-3023 Secretary :: +49 511 762-3267 Email :: flohr APVT itp PVNCTVM uni-hannover PVNCTVM de <<< Room :: 242 Building 3701 Office Hours :: Wednesdays 10-11 |

### :: Contents ::

Home | :: | This page. |

News | Blog | :: | My occasional Blog Deep Field on science, especially theoretical/mathematical physics and its implications to and relations with ethics, philosophy, culture, sociology etc. This includes all sorts of news and ‑‑> job openings in my group. |

Group | :: | Current and past members of my research group with some information on their respective research topics. |

Research | :: | A brief description of what research I am interested in. I also try to explain, why I am interested in fundamental research, and why I believe fundamental research is something very important and very precious for humanity. |

Publications | :: | Access to all my scientific papers and works. |

Talks | :: | A selection of scientific talks I gave on various occasions, mostly on conferences or workshops on theoretical physics. |

Teaching | :: | Access to all resources related to my teaching as a theoretical physicist. This includes descriptions of all the lectures and seminars I gave as well as all related material such as tutorials, tests, handouts etc. |

Essays | :: | A selection of essays and other work, which are not related to my professional work as a mathematical physicist. Furthermore, most of the essays of my wife Birgitt on topics in English Literature and Literature Criticism can be found here. |

Photos | :: | A small gallery of photo albums, mostly relating to events in my research group. |

Miscellanea | :: | Anything else I found worth putting on these pages. |

Vita | :: | Current version of my Curriculum Vitæ. |

Caveat | :: | The obligatory disclaimer and some hints on potential viewing problems with these pages. |

gpg key | :: | My public gpg key to ensure privacy. |

Social Media | :: | facebook :: google+ :: LinkedIn :: ResearchGate :: twitter :: xing |

### :: Motto ::

If you indeed want the men of the
world not to loose the qualities that are natural to them, you had best study
how it is that Heaven and Earth maintain their external course, that the sun
and moon maintain their light, the stars their serried ranks, the birds and
beasts their flocks, the trees and shrubs their station. Thus you shall learn
to guide your steps by Inward Power, to follow the course that the Way of
Nature sets; and soon you will reach a goal where you will no longer need to
go round laboriously advertising goodness and duty,
like the town-crier with his drum, seeking for news of a lost child.
[…]

All
this talk of goodness and duty, these perpetual pin-pricks, unnerve and
irritate the hearer; nothing, indeed, could be more destructive of his inner
tranquility.
[…]

The
swan does not need a daily bath in order to remain
white; the crow does not need a daily inking in order to remain black.

(Lao-tse, chiding Confucius for his moralizing)

### :: Background Image ::

The image which floats behind the text of all these pages is more or less
an image of the modular group $\mathrm{PSL}(2,\mathbb{Z})$, which I discovered
while working on the classification of all rational two-dimensional conformal
quantum field theories with effective central charge $c_{\textrm{eff}} \leq 1$.
Essentially, an element of $\mathrm{PSL}(2,\mathbb{Z})$ is a $2\times 2$ matrix
\[
M = \begin{pmatrix}
a & b\\
c & d
\end{pmatrix}
\]
with determinant $\mathrm{det}(M) = ad - bc = 1$.
One now plots $a/d$ versus
$b/c$ and transforms the resulting image to the unit disk via a
Poincaré map. The colouring stems from the algorithm used, which
creates the modular group as a binary tree and codes the colour of a point
according to its depth in the tree. Each element $M$ is then given
as a word in the letters $S$ and $T$, where
\[
S = \begin{pmatrix}
0 & -1\\
1 & 0
\end{pmatrix}\,,\ \ \ \
T = \begin{pmatrix}
1 & 1\\
0 & 1
\end{pmatrix}\,,
\]
with the additional relations $S^2 = (ST)^3 = 1$.
Of course, this is a highly simplified
description, the truth is — as always — much more complicated.
A high resolution image [4000x4000 :: 4.3MByte] with a fairly high depth of the binary tree (about $2^{40}$) can be found
‑‑> here.