Ingemar Bengtsson
My name is Ingemar Bengtsson, and I have
been a lecturer at Fysikum in Stockholm since '93 (and a professor since
'00). My previous "career" was at Chalmers, CERN and Imperial College.
This is me (as drawn by Jörgen Hansson in
'73)
The
research areas that I like the best usually have something to do with geometry.
General relativity is a favourite. Most of my work there is on black holes. My
strongest prejudice is that the world has four dimensions; this is the
direction in which I look for clues about quantum gravity. Then I work on
quantum information theory, since the geometry of the space of quantum states
is wonderful and rather mysterious. What I find fascinating about relativity
and quantum mechanicsas it happens, the two deepest theories we haveis
that their basic equations have been around for almost a hundred years, and yet
they keep springing conceptual surprises on us. I am looking for the next
surprise there, but I do keep a weather eye open on other subjects as well.
The things that are on my mind at the moment are Penrose inequalities, quasilocal mass,
complementary measurements in quantum mechanics, and the existence of
special sets of equiangular vectors in Hilbert
space (this translates in the laboratory into a very special kind of measurement, and in
mathematics to Hilbert's 12th problem).
I am told that some scientists think that there is something queer going on in
the Universe while others, on the whole, don't. I tend towards the former
viewpoint, but this is probably not apparent from my published papers. Some
examples of those are:
 Note on Massive Spin 2 in Curved Space(1994)
 2Form Geometry and the 'tHooftPlebanski
Action (1995)
 Galactic
Rotation Curves (1996)
 Black Holes and Wormholes in 2+1
Dimensions (1997)
 A Spinning Antide Sitter Wormhole (1998)
 De Sitter Space and Spatial Topology (1999)
 2+1 Gravity, Chaos and Time Machines (2000)
 CPn,
or, Entanglement Illustrated
(2001)
 How to Mix a Density Matrix (2002)
 Geometry of Black Hole Thermodynamics (2003)
 Birkhoff's Polytope
and Unistochastic Matrices, N = 3 and N = 4 (2004)
 Antide Sitter space, squashed and
stretched
(2005)
 Mubs and Hadamards
of order six
(2006)
 Note on nonmetric gravity (2007)
 A note on trapped surfaces in the Vaidya solution
(2008)
 Pentagrams and paradoxes (2009)

The region of trapped surfaces in spherical
symmetry, its core, and their boundaries (2010)

The monomial representations of the Clifford group (2011)

Families of complex Hadamard matrices (2012)

Trapped surfaces in OppenheimerSnyder black holes (2013)

States that are far from being stabilizer states (2014)

Clifford tori and unbiased vectors (2015)

A toy Penrose inequality and its proof (2016)

Dimension towers of SICs. I. Aligned SICs and embedded tight frames (2017)
Of course,
not all my papers are published.
With Karol Zyczkowski from Krakow
I have written a book on quantum mechanics, seen through our eyes. The Cambridge University Press published the second
edition in 2017:
I occasionally try to write popular
science articles. They are all in Swedish:
If you want to hear me trying to explain gravity (på svenska), you can do it from home.
In the department I am a member of the "KOMKO" group, which includes the
(informal) Relativity group (it has
a little homepage of its own), as well as the group for Quantum Information and Quantum Optics. Also,
Edwin Langmann (KTH) and I are organizing a weekly seminar in Mathematical Physics (on
Wednesdays at 11 o'clock).
My views on teaching happen to be identical to those of Fred Hoyle, as
expressed in " The Universe: Past and present reflections
" (Ann. Rev. Astr. Astrophys. 1982), so there is no need to repeat them here.
This academic year I teach Electrodynamics I, Advanced General Relativity, and Analytical Mechanics (in
English, since English speaking students are always welcome).
·
Elektrodynamik I. The book for the course is no less than that of J. D. Jackson,
3d ed. The course program
for 2017 is on the course homepage
.
The lecture notes
below have just a little to do with this course.
·
Avancerad allmän relativitetsteori. The emphasis was
on gravitational collapse, black holes, and the like. See the lecture notes below, and the homepage
.
· Analytisk mekanik. The official book is Goldstein, Poole och Safko: Classical
Mechanics, third edition.
This book is rather verbose, and in fact my course follows my own
lecture notes (see below). The program, including exercises,
for 2018 is on the course homepage
(in somewhat preliminary form).
Examples of lecture notes:
I enjoy
supervising Master's Theses and such things. I have made a little collection of all theses
that I have supervised, and saved the pdf files for,
here.
My present graduate students are Ole Andersson, and Irina Dumitru.
I am not supported by the totally corrupt Swedish Research Council (VR).
My Erdös number is 3. My Einstein number is 4. And one more thing. A quote from James Lovelock, which I
have had occasion to think about, quite some time ago actually:
"Of all the prizes that come from surviving more than fifty years, the
best is the freedom to be eccentric."
Many years later in Meknes. Photograph by Adan Cabello.
Email:
ibeng@fysik.su.se