What is the physics in higher dimensions? - ZARM

Wilhelm und Else Heraeus–Stiftung
418 th WE–Heraeus–Seminar
Models of Gravity
in Higher Dimensions
— From Theory to Experimental Search —
Program — Abstracts — Participants — Schedule
25 August – 29 August 2008
Hotel Landgut Horn, Bremen (Germany)

The ”Wilhelm und Else Heraeus-Stiftung” is a private foundation which
supports research and education in science, especially in physics. A major
activity is the organisation of seminars. To German physicists the foundation
is recognized as the most important private funding institution in their fields.
Some activities of the foundation are carried out in cooperation with the
German Physical Society (Deutsche Physikalische Gesellschaft).
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Aim and Purpose of the
418 th WE–Heraeus–Seminar
Why higher dimensions
Starting with Kaluza and Klein, the unification of the fundamental interactions
has ever since involved higher dimensions. In particular, string theory as
a major candidate for such a unified theory and thus also for quantum gravity,
needs higher dimensions for its consistency. The additional dimensions
might be small and compact, but there might also be large extra dimensions.
Detection of these would lead to exciting new physics to be discovered and
lead to a new picture of the universe.
Topics
The main topics of this seminar are
• Solutions of Einstein equations in higher dimensions
• Motion in higher dimensional space–times
• Black holes in high energy particle collision
• Experimental search for higher dimensions
Leading experts in the field will give an overview of the whole subject.
The seminar is devoted to diploma students, PhD students and researchers.
3

Scientific Organization
Prof. Dr. Jutta Kunz
PD Dr. Claus Lämmerzahl
Institute of Physics
Carl von Ossietzky University Oldenburg
Postfach 2503
26111 Oldenburg
Germany
kunz@theorie.physik.uni-oldenburg.de
ZARM
University of Bremen
Am Fallturm
28359 Bremen
Germany
laemmerzahl@zarm.uni-bremen.de
4

Venue
Place
Meeting room
Registration
Conference e-mail
Hotel Landgut Horn
Leher Heerstraße 140
28357 Bremen
Germany
Phone +49 (0) 421 25 89 0
Fax +49 (0) 421 25 98 222
info@landgut-horn.de
Conference room
Monday morning;
Monday to Wednesday
during lunch and coffee breaks.
laemmerzahl@zarm.uni-bremen.de
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7
Program

Monday, 25 August 2008
08:50 – 09:00 Welcome by Organizers and Heraeus foundation
09:00 – 09:50 Hidden Symmetries of Higher Dimensional Black Holes I
Valeri Frolov
09:50 – 10:40 String theory: introduction - status - outlook I
Stefan Theisen
10:40 – 11:10 Coffee break
11:10 – 12:00 String theory: introduction - status - outlook II
Stefan Theisen
12:00 – 12:50 Rotating black holes in higher dimensions:
non–uniqueness, counterrotation and negative horizon mass
Jutta Kunz
12:50 – 15:00 Lunch
15:00 – 15:50 Hidden Symmetries of Higher Dimensional Black Holes II
Valeri Frolov
15:50 – 16:40 Experimental Tests with Atomic Clocks I
Eckehard Peik
16:40 – 17:10 Coffee break
17:10 – 18:00 Experimental Tests with Atomic Clocks II
Eckehard Peik
18:00 – 18:20 Higher dimensional Kerr-Schild spacetimes
Marcello Ortaggio
18:20 – 18:40 No higher-dimensional C-metric in the Robinson-Trautman family
Jiri Podolsky
19:00 Social Dinner
8

Tuesday, 26 August 2008
09:00 – 09:50 String theory: introduction - status - outlook III
Stefan Theisen
09:50 – 10:40 Nonuniform Black Strings
Burkhard Kleihaus
10:40 – 11:10 Coffee break
11:10 – 12:00 D-dimensional black holes and black strings in the
presence of a cosmological constant
Yves Brihaye
12:00 – 12:50 Gravitating non-Abelian solitons and hairy black holes
in higher dimensions
Michael Volkov
12:50 – 15:00 Lunch
15:00 – 15:50 What is the physics in higher dimensions
Claus Lämmerzahl
15:50 – 16:40 Tests of the gravitational inverse-square law:
motivations, techniques and results I
Eric Adelberger
16:40 – 17:10 Coffee break
17:10 – 18:00 Tests of the gravitational inverse-square law:
motivations, techniques and results II
Eric Adelberger
18:00 – 18:20 Solitonic solution generating technique
and black ring solutions
Hideo Iguchi
18:20 – 18:40 The boundary counterterm method in Einstein-Gauss-
Bonnet theory with negative cosmological constant
Eugen Radu
19:00 Dinner
20:30 Poster session
9

Wednesday, 27 August 2008
09:00 – 09:50 Undeformed and deformed non-abelian black strings
Betti Hartmann
09:50 – 10:40 Black holes in Gauged Supergravity Theories I
Miriam Cvetič
10:40 – 11:10 Coffee break
11:10 – 12:00 Black holes in Gauged Supergravity Theories II
Miriam Cvetič
12:00 – 12:50 On integrability and separability in the spacetimes
of Kerr-NUT-(A)dS black holes
Pavel Krtouš
12:50 – 13:50 Lunch
14:00 – 18:30 Excursion
19:00 Dinner
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Thursday, 28 August 2008
09:00 – 09:50 Black holes in Gauged Supergravity Theories III
Miriam Cvetic
09:50 – 10:40 Black Hole – Black String Transition
Barak Kol
10:40 – 11:10 Coffee break
11:10 – 12:00 Field Theory Methods in Gravitation
Barak Kol
12:00 – 12:50 Mini Black Holes: Will they be created
What can we learn from them
Panagiota Kanti
12:50 – 15:00 Lunch
15:00 – 15:50 Mini Black Holes: Will they be created
What can we learn from them
Panagiota Kanti
15:50 – 16:40 Illuminating hidden sectors of nature
Andreas Ringwald
16:40 – 17:10 Coffee break
17:10 – 18:00 Illuminating hidden sectors of nature
Andreas Ringwald
18:00 – 18:20 Charged black saturns
Cristian Stelea
18:20 – 18:40 Black hole formation in high-energy particle collisions
Hirotaka Yoshino
19:00 Dinner
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Friday, 29 August 2008
09:00 – 09:50 Static Solutions of Generalized Einstein–Yang-Mills–Higgs Models
Peter Breitenlohner
09:50 – 10:40 Sigma-model approaches to exact solutions in
higher-dimensional gravity and supergravity I
Gerard Clement
10:40 – 11:10 Coffee break
11:10 – 12:00 Sigma-model approaches to exact solutions in
higher-dimensional gravity and supergravity II
Gerard Clement
12:00 – 12:50 Gravitating Yang-Mills fields
Tigran Tchrakian
12:50 – 15:00 Lunch
16:15 – 16:30 Coffee break – End of seminar
19:00 Dinner
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13
Abstracts

Tests of the gravitational inverse-square law: motivations,
techniques and results
Eric Adelberger
(University of Washington, Seattle)
It is remarkable that small-scale experiments can address important open
issues in fundamental science such as: “why is gravity so weak” and “why
is the cosmological constant so small” and “what is the real number of
space dimensions in the Universe” String theory ideas (new scalar particles
and extra dimensions) and other notions hint that Newton’s Inverse-Square
Law could break down: perhaps at distances less than 1 mm, perhaps at
the astronomical scale. I will review the motivations for testing the Inverse-
Square Law, and discuss recent experiments with torsion balances and with
laser-ranging to the moon. Our torsion-balance experiments at separations
down to 57 microns exclude gravitational-strength Yukawa interactions with
length scales greater than about 56 micrometers (approximately the diameter
of a human hair), and set a robust 95% confidence upper limit of 44 micrometers
on the size of an extra dimension. The APOLLO laser-ranging facility
is now providing lunar ranges with millimeter precision, which will lead to
substantial improvements in several key tests of the fundamental properties
of gravity.
[1] D.J. Kapner et al.: Phys. Rev. Lett. 98, 021101 (2007).
[2] E.G. Adelberger et al.: Phys. Rev. Lett. 98, 13104 (2007).
[3] N. Arkani-Hamed, S. Dimopoulos and G. Dvali: The Universe’s Unseen
Dimensions, Scientific American, August 2000, Vol. 283 Issue 2.
[4] E.G. Adelberger, B.R. Heckel and A.E. Nelson: Tests of the Gravitational
Inverse Square Law, Annual Reviews of Nuclear and Particle
Science 53, 77 (2003).
[5] E.G. Adelberger, B.R. Heckel and C.D. Hoyle: Testing the Gravitational
Inverse-square Law, Physics World 18, 41-45 (April 2005).
14

Static Solutions of Generalized Einstein–Yang-Mills–
Higgs Models
Peter Breitenlohner
(Werner-Heisenberg-Institute, Munich)
We study generalized Yang-Mill models with action ( ∧ p
1 F )2 coupled to a
Higgs field with action ( ∧ p−1
1 FDΦ)2 in D =4p space-time dimensions. In
flat space these models have Bogomol’nyi solutions generalizing those for
the p = 1 Prasad-Sommerfield monopole. When coupled to gravity with the
action ∧ p
1 R these models have static solutions rather similar to those of the
gravitating Prasad-Sommerfield monopole.
[1] P. Breitenlohner, P. Forgács, and D. Maison: Nucl. Phys. B 442 (1995)
126.
[2] E. Radu, C. Stelea, and D. H. Tchrakian: arXiv:gr-qc/0601098.
[5] E. Radu and D. H. Tchrakian: arXiv:hep-th/0502025.
15

D-dimensional black holes and black strings in the
presence of a cosmological constant
Yves Brihaye
(Mons)
It is known from some time that a cosmological constant can affect the physical
properties of 4-dimensional solitons and sphalerons (and their black holes
counterparts) once considered in the presence of gravity. Higher-dimensional
gravity leads to much richer classes of new classical solutions than in fourdimensions.
In addition to black holes, black strings, black branes and black
rings can be constructed. These solutions are to a large extend characterized
by topology of their horizon. While some of these solutions, e.g. black
rings, can be constructed analytically in the case of an asymptotically flat
space-time, the equations become untractable algebraically in the presence
of a cosmological constant. The solutions can be constructed, however by
using numerical methods. We will present several families of such solutions
and discuss some of their aspects: coupling to electromagnetism, to Yang-
Mills, effect of a rotation and effect of a Gauss-Bonnet term. The stability
of AdS black strings will also be discussed in relation with the Gubser-Mitra
conjecture.
[1] Y. Brihaye and E. Radu: Five-dimensional rotating black holes in Einstein-
Gauss-Bonnet theory, arXiv:0801.1021 [hep-th] (to appear in Phys.
Lett. B)
[2] Y. Brihaye, T. Delsate, and E. Radu: On the stability of AdS black
strings, arXiv:0710.4034 [hep-th]
[3] Y. Brihaye, E. Radu, and D.H. Tchrakian: AdS 5 rotating non-Abelian
black holes, Phys. Rev. D76, 105005 (2007), arXiv:0707.0552 [hep-th]
[4] Y. Brihaye and E. Radu: Magnetic solutions in AdS 5 and trace anomalies,
Phys. Lett. B658, 164 (2008), arXiv:0706.4378 [hep-th]
[5] Y. Brihaye and T. Delsate: Charged-rotating black holes and black
strings in higher dimensional Einstein-Maxwell theory with a positive
cosmological constant, Class. Quant. Grav. 24, 4691 (2007), grqc/0703146
[6] Y. Brihaye, E. Radu, and C. Stelea: Black strings with negative cosmological
constant: Inclusion of electric charge and rotation, Class. Quant.
Grav. 24, 4839 (2007), hep-th/0703046
16

[7] Y. Brihaye and T. Delsate: Black strings and solitons in five dimensional
space-time with positive cosmological constant, Phys. Rev. D75, 044013
(2007), hep-th/0611195
[8] Y. Brihaye, E. Radu, Eugen and D.H. Tchrakian: Einstein-Yang-Mills
solutions in higher dimensional de Sitter spacetime, Phys. Rev. D75,
024022 (2007), gr-qc/0610087
[9] Y. Brihaye and E. Radu: Kaluza-Klein black holes with squashed horizons
and d = 4 superposed monopoles, Phys. Lett. B641, 212 (2006),
hep-th/0606228
17

Sigma-model approaches to exact solutions in higherdimensional
gravity and supergravity
Gerard Clement
(Annecy)
Classical gravitating field theories reduced to three dimensions admit manifest
gauge invariances and hidden symmetries, which together make up the
invariance group G of the theory. If this group is large enough, the target
space is a symmetric space G/H. New solutions may be generated by the
action of invariance transformations on a seed solution. Another application
is the construction of multicenter solutions from null geodesics of the target
space. After a general introduction on this sigma-model approach, I will
discuss the case of five-dimensional gravity, with invariance group SL(3,R),
and five-dimensional minimal supergravity, with invariance group G 2 . I will
then summarize recent applications to the generation of new charged rotating
black ring solutions.
[1] G. Clément: Solutions of five-dimensional general relativity without
spatial symmetry, Gen. Rel. Grav. 18, 861 (1986).
[2] G. Clément: From Schwarzschild to Kerr: generating spinning Einstein-
Maxwell fields from static fields, Phys. Rev. D 57, 4885 (1998); grqc/9710109.
[3] G. Clément and C. Leygnac: Non-asymptotically flat, non-AdS dilaton
black holes, Phys. Rev. D 70, 084018 (2004); (gr-qc/0405034).
[4] A.Bouchareb,C.M.Chen,G.Clément, D.V. Gal’tsov, N.G. Scherbluk
and T. Wolf: G2 generating technique for minimal D=5 supergravity
and black rings, Phys. Rev. D 76, 104032 (2007); arXiv:0708.2361[hepth].
[5] G. Clément: The symmetries of five-dimensional minimal supergravity
reduced to three dimensions, arXiv:0710.1192, J. Math. Phys. 49,
042503 (2008); arXiv:0710.1192[gr-qc].
18

Black holes in Gauged Supergravity Theories
Miriam Cvetič
(Philadelphia)
We present general charged spinning black holes in asymptotically antideSitter
space-times in diverse dimensions. These are solutions of gauged
supergravity theories, i.e. effective theories of consistent sphere reductions of
string theories. As such these solutions play an important role in gauge theory/gravity
duality. Euclidean solutions and supersymmetric limits of such
black holes are also presented.
[1] M. Cvetič and J.F. Vazquez-Poritz: Warped Resolved L a,b,c Cones, ar-
Xiv:0705.3847 [hep-th].
[2] Z.W. Chong, M. Cvetič, H. Lu and C.N. Pope: Non-extremal rotating
black holes in five-dimensional gauged supergravity, Phys. Lett. B 644,
192 (2007) [arXiv:hep-th/0606213].
[3] Z.W. Chong, M. Cvetič, H. Lu and C.N. Pope: General non-extremal
rotating black holes in minimal five-dimensional gauged supergravity,
Phys. Rev. Lett. 95, 161301 (2005) [arXiv:hep-th/0506029].
[4] M. Cvetič, H. Lu, D.N. Page and C.N. Pope: New Einstein-Sasaki
spaces in five and higher dimensions, Phys. Rev. Lett. 95, 071101 (2005)
[arXiv:hep-th/0504225].
19

Hidden Symmetries of Higher Dimensional Black
Holes
Valeri Frolov
(Edmonton )
The most general known solution describing higher dimensional rotating
black holes with NUT parameters in an asymptotically (anti) de Sitter spacetime
is a Kerr-NUT-(A)dS metric. We demonstrate that this metric possesses
a principal CKY tensor, that is a second rank closed conformal Killing-Yano
tensor. This tensor generates a ‘tower’ of Killing-Yano and Killing tensors,
which together with the existing Killing vectors are sufficient for the complete
integrability of geodesic equations and the separation of variables in the
Hamilton-Jacobi, Klein-Gordon and Dirac equations. We also show that these
hidden symmetries, generated by the principal CKY tensor, allow one to
solve the equations for a stationary string configurations and the equations
for the parallel transport of the frame along geodesics in these spacetimes.
These ‘miraculous’ properties of the higher dimensional Kerr-NUT-(A)dS
metrics make them quite similar to the their 4-dimensional ‘cousin’.
[1] V.P. Frolov and D. Kubiznak: Higher-Dimensional Black Holes: Hidden
Symmetries and Separation of Variables, to appear in Class. Quant.
Grav. arXiv:0802.0322 [hep-th],
[1] P. Connell, V.P. Frolov, D. Kubiznak: Solving parallel transport equations
in the higher-dimensional Kerr-NUT-(A)dS spacetimes. arXiv:0803.3259
20

Undeformed and deformed non-abelian black strings
Betti Hartmann
(Bremen)
Motivated by theories in higher dimensions such as Kaluza-Klein theories,
superstring theories and brane world models, black holes in higher dimensions
have gained a lot of interest in recent years. A variety of different black
hole solutions have been constructed and discussed such as hyperspherically
symmetric black holes, black strings, black branes and black rings.
While most solutions have been constructed in “pure” (dilaton-)gravity
theories, my talk will be concerned with higher dimensional black hole solutions
in theories where non-abelian gauge fields are minimally coupled to
gravity. I will mention hyperspherically symmetric black hole in 5 dimensions
with horizon topology S 3 (see [1]), but will mainly focus on so-called undeformed
and deformed non-abelian black strings with horizon topology S 2 × S 1 .
These solutions are translationally invariant and correspond to 4-dimensional
(spherically or axially symmetric) non-abelian black holes trivially extended
into one extra dimensions [2,3,4].
[1] Y. Brihaye, A. Chakrabarti, B. Hartmann and D.H. Tchrakian, Higher
order curvature generalizations of Bartnick-McKinnon and colored
black hole solutions in D = 5, Phys. Lett. B 561, 161 (2003).
[2] B. Hartmannm, Non-Abelian black strings, Phys. Lett. B 602, 231
(2004).
[3] Y. Brihaye and B. Hartmann, Deformed black strings in 5-dimensional
Einstein-Yang-Mills theory, Class.Quant.Grav. 22, 5145 (2005).
[4] Y. Brihaye, B. Hartmann and E. Radu, Black strings in (4+1)-dimensional
Einstein-Yang-Mills theory, Phys.Rev. D 72, 104008 (2005).
21

Mini Black Holes: Will they be created What can
we learn from them
Panagiota Kanti
(Ioannina)
The new theories that postulate the existence of additional spacelike dimensions
in nature have given a new momentum to the study of black hole
solutions in a higher-dimensional spacetime. The introduction of the concept
of the brane, as our 4-dimensional world embedded in a spacetime with one
or more extra dimensions, has given rise to new ideas, as well as to new
problems, regarding the existence of consistent gravitational solutions, their
interpretation and potential observable effects for the localised-on-the-brane
observer. While in the context of models with warped extra dimensions the
construction of analytical brane-world solutions has proven to be particularly
challenging, in the presence of large extra dimensions the analysis may be
significantly simplified under appropriate assumptions. Thus, the interest has
turned to phenomenological implications such as the possibility of the creation
of a black hole during a high-energy particle collision, the modification
of the decay process and its observable effects on our brane. In this talk, I
will briefly review the main developments in this field of research.
[1] P. Kanti: Black Holes at the LHC, arXiv:0802.2218 [hep-th].
[2] P. Kanti: Black holes in theories with large extra dimensions: A review,
Int. J. Mod. Phys. A19 (2004) 4899 (hep-ph/0402168).
[3] B. Webber: Black holes at accelerators, hep-ph/0511128.
[4] T. Banks and W. Fischler: A model for high energy scattering in quantum
gravity, hep-th/9906038.
22

Nonuniform Black Strings
Burkhard Kleihaus
(Oldenburg)
In D-dimesional space-time with some compact dimensions the vacuum solutions
comprise besides the black holes also black strings, if D>4. Whereas
the black holes have horizon topology SD-2, the black strings have horizon
topology S D−2 ×S 1 . Uniform black strings (UBS) are tranlationally invariant
in direction of the compact dimension, but become unstable at the Gregory-
Laflamme point. Nonuniform black strings (NUBS) emerge from the UBS
at the Gregory-Laflamme point. The geometry of their horzion resembles a
deformed cylinder. In the limit of infinite deformation a topology changing
configuration is expected, where the branchoftheNUBSmergeswiththe
branch of black holes.
First NUBS in five and six dimensions will be considered and their physical
properties discussed. Then we will focus on the interior of the horzion of
six dimensional NUBS. Next we will discuss the stationary rotating generelizations
of NUBS. Finally we will demonstrate how black string solutions of
Einstein-Maxwell-dilaton theory can be generated from the vacuum solutions
by a Harrison transformation.
23

Field Theory Methods in Gravitation
Barak Kol
(Jerusalem )
Applications of Classical Effective Field Theory (CLEFT) methods to gravity
are growing. In the talk, Feynman diagrams, regularization and renormalization
will be applied to several gravitational problems including: matched
asymptotic expansion and caged black holes; Post-Newtonian expansion
(Non-Relativistic Gravitation) and binary system; and possibly others to appear
by the time of talk.
[1] B. Kol and M. Smolkin: Classical Effective Field Theory and Caged
Black Holes, arXiv:0712.2822
[2] B. Kol and M. Smolkin: Non-Relativistic Gravitation: From Newton to
Einstein and Back, arXiv:0712.4116
24

On integrability and separability in the spacetimes
of Kerr-NUT-(A)dS black holes
Pavel Krtouš
(Praha)
In the talk of V. Frolov we learn that the Kerr-NUT-(A)dS spacetime, describing
a generally rotating black hole in higher dimension, is endowed with
explicit and hidden symmetries encoded in the series of Killing vectors and
Killing-Yano tensors. In this talk we show how to use these objects to construct
a full set of commuting integrals of motion for a geodesic motion and
prove thus its complete integrability. Such an integrability is closely related
to the separability of the Hamilton-Jacobi equation which also follows from
the WKB approximation of the Klein-Gordon equation. Using the secondrank
Killing tensors related to the integrals of motion we are even able to
construct a full set of commuting symmetry operators of the Klein-Gordon
equation. The separability of the equations for eigenfunctions of these operators
is then manifestly demonstrated by an explicit construction of the
common eigenfunctions. We also comment on the progress of finding a general
test electromagnetic field and, finally, give some remarks on a geometrical
interpretation of the Jacobi coordinates in which the discussed separability
have been achieved.
[1] D.N. Page, D. Kubiznák, M. Vasudevan, and P. Krtouš: Complete Integrability
of Geodesic Motion in General Higher-Dimensional Rotating
Black Hole Spacetimes, Phys. Rev. Lett. 98 (2007) 061102, hepth/0611083
[2] V.P. Frolov, P. Krtouš, and D. Kubiznák: Separability of Hamilton-
Jacobi and Klein-Gordon Equations in General Kerr-NUT-AdS Spacetimes,
J. High Energy Phys. 0702 (2007) 5, hep-th/0611245
[3] P. Krtouš, D. Kubiznák, D.N. Page, V.P. Frolov: Killing-Yano Tensors,
Rank-2 Killing Tensors, and Conserved Quantities in Higher Dimensions,
J. High Energy Phys. 0702 (2007) 4, hep-th/0612029
[4] P. Krtous: Electromagnetic Field in Higher-Dimensional Black-Hole
Spacetimes, Phys. Rev. D 76 (2007) 084035, arXiv:0707.0002
[5] A. Sergyeyev, P. Krtouš: Complete Set of Commuting Symmetry Operators
for KleinGordon Equation in Generalized Higher-Dimensional
Kerr-NUT-(A)dS Spacetimes, Phys. Rev. D 77 (2008) 044033, arXiv:0711.4623
25

Rotating black holes in higher dimensions: non–
uniqueness, counterrotation and negative horizon
mass
Jutta Kunz
(Oldenburg)
In D = 4 dimensions the Kerr-Newman solutions present the unique family of
stationary asymptotically flat black holes of Einstein-Maxwell (EM) theory.
The corresponding D¿4 charged rotating black holes of EM theory have not
yet been obtained in closed form, but subsets have been obtained numerically,
in particular, black holes in odd dimensions with equal-magnitude angular
momenta. When a Chern-Simons (CS) term is added to the EM action, the
resulting stationary black hole solutions possess surprising properties. When
the CS coefficient is increased beyond its supergravity value, counterrotating
black holes appear, whose horizon rotates in the opposite sense to the angular
momentum. Black holes may also possess a negative horizon mass, while
their total mass is positive. Moreover black holes are no longer uniquely
characterized by their global charges. Finally, charged rotating black holes
with negative cosmological constant are discussed.
[1] J. Kunz, F. Navarro-Lérida, and A. K. Petersen: Five-Dimensional
Charged Rotating Black Holes, Phys. Lett. B614, 104 (2005), gr-qc/0503010.
[2] J. Kunz, F. Navarro-Lrida: D=5 Einstein-Maxwell-Chern-Simons Black
Holes, Phys. Rev. Lett. 96, 081101 (2006), hep-th/0510250.
[3] J. Kunz, D. Maison, F. Navarro-Lérida, and J. Viebahn: Rotating
Einstein-Maxwell-Dilaton Black Holes in D Dimensions, Phys. Lett.
B639, 95 (2006), hep-th/0606005.
[4] J.Kunz,F.Navarro-Lérida, and J. Viebahn: Charged Rotating Black
Holes in Odd Dimensions, Phys. Lett. B639, 362 (2006), hep-th/0605075
[5] J.Kunz,F.Navarro-Lérida: Negative Horizon Mass for Rotating Black
Holes, Phys. Lett. B643, 55 (2006), hep-th/0610036.
[6] J.Kunz,F.Navarro-Lérida: Non-Uniqueness, Counterrotation, and Negative
Horizon Mass of Einstein-Maxwell-Chern-Simons Black Holes,
Mod. Phys. Lett. A21, 2621 (2006), hep-th/0610075.
[7] J.Kunz,F.Navarro-Lérida, and E. Radu: Higher Dimensional Rotating
Black Holes in Einstein-Maxwell Theory with Negative Cosmological
Constant, Phys. Lett. B649 463 (2007), gr-qc/0702086.
26

What is the physics in higher dimensions
Claus Lämmerzahl
(Bremen)
Usually physical laws are transscribed to higher dimensions by leaving Gauss’
law or similar features unchanged [1,2]. This leads to modifications of the
interaction potentials like Newton or Coulomb potential or the space-time
metric in higher dimensions. Here we proceed another way: If we assume
that, e.g., the Keplerian motions are thesameinhigherdimensions,then
the gravitational potential in higher dimension should have the same form
as in three dimensions. This asks for a modification of the gravitational field
equation which now has to be of pseudo-differential operator form [3]. We
determine the field equations and discuss observational consequences. We
also discuss other observational criteria like Huygens principle which depend
on the dimensionality of space-time [4].
[1] P. Ehrenfest: Welche Rolle spielt die Dimensionalitt des Raumes in den
Grundgesetzen der Physik, Ann. Phys. (Leipzig) 61, 440 (1920).
[1] J. D. Barrow: Dimensionality, Philos. Trans. R. Soc. London, Ser. A
310, 337 (1983).
[1] F. Burgbacher, C. Lämmerzahl, A. Macias: Is there a stable hydrogen
atom in higher dimensions, J. Math. Phys. 40, 625 (1999).
[1] C. Lämmerzahl, A. Macias: On the Dimensionality of Space-Time, J.
Math. Phys. 34, 4540 (1993).
27

Experimental Tests with Atomic Clocks
Ekkehard Peik
(PTB Braunschweig)
Atomic clocks are the most precise measuring devices constructed by mankind
and consequently they play a prominent role in experimental tests of
Relativity and in a search for New Physics. I will review recent tests of aspects
of the equivalence principle like searches for violation of local position invariance
or temporal variations of fundamental constants with atomic clocks of
different kind.
[1] S.G. Karshenboim and E. Peik (Eds.): Astrophysics, Clocks and Fundamental
Constants, Lecture Notes in Physics , Vol. 648 (Springer,
Heidelberg, 2004)
[2] S.G. Karshenboim, V. Flambaum, and E. Peik: Atomic Clocks and
Constraints on Variations of Fundamental Constants, arXiv:physics/0410074
[3] P. Wolf et al.: Quantum Physics Exploring Gravity in the Outer Solar
System: The Sagas Project, arXiv:0711.0304
28

Illuminating hidden sectors of nature
Andreas Ringwald
(DESY Hamburg)
Most embeddings of the standard model into a more unified theory, in particular
the ones based on supergravity or superstrings, predict the existence
of a hidden sector of particles and interactions which have only very weak
interactions with the visible sector standard model particles. The gauge interactions
in the hidden sector generically involve several U(1) factors. Usually,
it is assumed that the corresponding gauge bosons are very heavy, in order to
avoid eventual bservational constraints from low energy experiments. However,
in realistic string compactifications, some of these hidden photons may
indeed be light, with masses in the sub-eV range. In this case, the dominant
interaction with the visible sector photon will be through gauge kinetic
mixing. Moreover, hidden sector matter particles charged under such U(1)s
will acquire some effective electric charge proportional to the kinetic mixing
angle. Correspondingly, such light hidden sector particles may be searched
for in experiments exploiting high fluxes of low energy photons and/or large
electromagnetic fields. We will present a review of this emerging low energy
frontier of fundamental physics.
[1] H. Gies, J. Jaeckel and A. Ringwald: Polarized light propagating in a
magnetic field as a probe of millicharged fermions, Phys. Rev. Lett. 97,
140402 (2006). arXiv:hep-ph/0607118
[2] H. Gies, J. Jaeckel and A. Ringwald: Accelerator cavities as a probe
of millicharged particles, Europhys. Lett. 76, 794 (2006). arXiv:hepph/0608238
[3] S.A. Abel, J. Jaeckel, V.V. Khoze and A. Ringwald: Illuminating the
hidden sector of string theory by shining light through a magnetic field,
Phys. Lett. B (2008) (in print). arXiv:hep-ph/0608248
[4] M. Ahlers, H. Gies, J. Jaeckel and A. Ringwald: On the particle interpretation
of the PVLAS data: Neutral versus charged particles, Phys.
Rev. D 75, 035011 (2007). arXiv:hep-ph/0612098
[5] M. Ahlers, H. Gies, J. Jaeckel, J. Redondo and A. Ringwald: Light from
the Hidden Sector, Phys. Rev. D 76, 115005 (2007). arXiv:0706.2836
[hep-ph]
[6] J. Jaeckel and A. Ringwald: A Cavity Experiment to Search for Hidden
Sector Photons, Phys. Lett. B 659, 509 (2008). arXiv:0707.2063 [hepph]
29

[7] A. Lindner and A. Ringwald: The Low-Energy Frontier, Phys. World
20N8, 32 (2007)
[8]M.Ahlers,H.Gies,J.Jaeckel,J.RedondoandA.Ringwald:Laser
experiments explore the hidden sector, Phys. Rev. D (2008) (in print).
arXiv:0711.4991 [hep-ph]
[9] S.A. Abel, M.D. Goodsell, J. Jaeckel, V.V. Khoze and A. Ringwald:
Kinetic Mixing of the Photon with Hidden U(1)s in String Phenomenology,
arXiv:0803.1449 [hep-ph]
30

Gravitating Yang-Mills fields
Tigran Tchrakian
(Dublin)
Review of work on the extension of gravitating Yang-Mills solutions to arbitrary
dimensions. The higher dimensional gauge field systems involved necessarily
include higher order terms in the Yang-Mills curvature, while the
corresponding gravitational systems involved can be restricted to the usual
Einstein-Hilbert actions. Exercising the option of employing gravitational
systems that are higher order in the Riemann curvature however result in
solutions with particularly interesting properties.
[1] E. Radu, D.H. Tchrakian, Y. Yang: Spherically symmetric selfdual
Yang-Mills instantons on curved backgrounds in all even dimensions.
Phys. Rev. D 77, 044017 (2008), arXiv:0707.1270 [hep-th]
[2] E. Radu, Ya. Shnir, D.H. Tchrakian: d=4+1 gravitating nonabelian
solutions with bi-azimuthal symmetry. Phys. Lett. B 657, 246 (2007),
arXiv:0705.3608 [hep-th]
[3] P. Breitenlohner, D. Maison, D.H. Tchrakian: Regular solutions to higher
order curvature Einstein-Yang-Mills systems in higher dimensions,
Class. Quantum Grav. 22, 5201 (2005), gr-qc/0508027
[4] Y.Brihaye,A.Chakrabarti,B.Hartmann, D.H. Tchrakian: Higher order
curvature generalizations of Bartnick-McKinnon and colored black
hole solutions in D = 5, Phys. Lett. B 561, 161 (2003), hep-th/0212288
[5] Y. Brihaye, A. Chakrabarti, D.H. Tchrakian: Particle - like solutions
to higher order curvature Einstein-Yang-Mills systems in d-dimensions,
Class. Quantum Grav. 20, 2765 (2003), hep-th/0202141
31

String theory: introduction - status - outlook
Stefan Theisen
(Golm)
No abstract
32

Gravitating non-Abelian solitons and hairy black
holes in higher dimensions
Michael Volkov
(Tours)
A short review of classical solutions with gravitating Yang-Mills fields, with
or without supersymmetry.
[1] M.S.Volkov, hep-th/0612219
[2] D.V. Gal’tsov, E.A. Davydov and M.S. Volkov, Phys. Lett. B 648, 249
(2007).
[3] A. Chamseddine and M.S.Volkov, Phys. Rev. D 70, 086007 (2004).
33

Short talks
Solitonic solution generating technique and black ring solutions
Hideo Iguchi (Chiba)
Higher dimensional Kerr-Schild spacetimes
Marcello Ortaggio (Prague)
No higher-dimensional C-metric in the Robinson-Trautman family
Jiri Podolsky (Prague)
Einstein-Gauss-Bonnet theory with negative cosmological constant and
the boundary counterterm method
Eugen Radu (Tours)
Charged black saturns
Cristian Stelea (Vancouver)
Black hole formation in high-energy particle collisions
Hirotaka Yoshino (Edmonton)
34

Posters
Black Hole Formation in High-Energy Particle Collisions
Hirotaka Yoshino (University of Alberta, Canada)
Five-Dimensional Black Hole Capture Cross Sections
Cisco Gooding, Andrei Frolov (Department of Physics, Simon Fraser University
)
Distored Weyl Solutions in Higher Dimensions
Shohreh Abdolrahimi, Andrey A. Shoom (Department of Physics, University
of Alberta, Canada)
Gravitational Wave Contributions to Entropy Fluctuations in Early Inflationary
Cosmology
Andrew W. Beckwith (Fermi Lab)
Photon Capture in a Rotating Dilaton Black Hole
Kenta Hioki (Department of Physics, Waseda University, Japan)
Umpei Miyamoto (Racah Institute of Physics, Hebrew University=
Quasinormal Modes of Black Holes Localized on the Randall-Sundrum
2-brane
Masato Nozawa, Tsutomu Kobayashi (Waseda University, Japan)
35

37
Participants

List of participants
Name, Title First name Address
Abdolrahimi Shohreh University of Alberta
CEB, 11322-89 Ave, Physics Department
University of Alberta, Edmonton, Alberta, Canada, T6G 2G7
Adelberger Eric Center for Experimental Nuclear Physics and Astrophysics,
University of Washington,
Seattle, WA, 98195
USA
Balcerzak Adam Univeristy of Szczecin Wielkopolska 15,
Szczecin,
Poland.
Beckwith Andrew Fermi National Laboratory
USA
Breitenlohner Peter Max-Planck-Institut für Physik
(Werner-Heisenberg-Institut)
Föhringer Ring 6
D-80805 München
Germany
Breuer Heinz-Peter Hanse-Wissenschaftkolleg Delmenhorst
Delmenhorst
Germany
Brihaye Yves Faculté des Sciences
Université de Mons-Hainaut
7000 Mons
Belgium
Chakrabarti Amitabha Centre de Physique Théorique
Ecole Polytechnique
91128 Palaiseau Cedex
France
Clement Garard Laboratoire de Physique Theorique LAPTH
BP 110
74941 Annecy-le-Vieux cedex
France
Cvetic Mirjam Department of Physics and Astronomy
University of Pennsylvania
Philadelphia
USA
Dittus Hansjörg ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany
Frolov Valeri Department of Physics
University of Alberta
Edmonton AB Canada
T6G 2J1
Canada
Giulini Domenico Max-Planck-Institut für Gravitationsphysik
Albert-Einstein-Institut
Am MÜhlenberg 1
14476 Golm
Germany

Göklü Ertan ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany
Gooding Cisco Simon Fraser University
8888 University Drive
Burnaby, B.C., V5A 1S6
Canada
Hackmann Eva ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany
hackmann@zarm.uni-bremen.de
Hartmann Betti School of Engineering and Science
Jacobs University Bremen
Research III, Room 66
28759 Bremen
Germany
Hioki Kenta Dept. of Physics, Waseda University
3-4-1-#55N-307 Okubo,
Shinjuku-ku,
Tokyo 169-8555
Japan
Iguchi Hideo Nihon University
Narashinodai,
Funabashi,
Chiba 274-8501,
Japan
Jakimowicz Malgorzata University of Warsaw, Institute of Theoretical Physics
Hoza 69
00-681 Warsaw
Poland
Kagramanova Valeria Department of Physics
Carl von Ossietzky University Oldenburg
26111 Oldenburg
Germany
Kanti Panagiota Department of Physics
University of Ioannina
Ioannina GR-45110
Greece
Kleihaus Burkhard Department of Physics
Carl von Ossietzky University Oldenburg
26111 Oldenburg
Germany
Kol Barak Racah Institute of Physics
Hebrew University
Jerusalem 91904
Israel
Krtous Pavel Institute of Theoretical Physics
Faculty of Mathematics and Physics
Charles University in Prague
V Holešovickách 2
180 00 Prague 8
Czech Republic
Kunz Jutta Department of Physics
Carl von Ossietzky University Oldenburg
26111 Oldenburg
Germany
kunz@theorie.physik.uni-oldenburg.de

Lämmerzahl Claus ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany
laemmerzahl@zarm.uni-bremen.de
Lechtenfeld Olaf Institute for Theoretcial Physics
Leibniz University Hannover
Appelstr. 2
30167 Hannover
Germany
Leissner Daniel Department of Physics
Carl von Ossietzky University Oldenburg
26111 Oldenburg
Germany
List meike ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany
Lorek Dennis ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany
Nozawa Masato Waseda University
55N-307, Department of Physics
Okubo 3-4-1
Shinjuku-ku
Tokyo 169-8555
Japan
Ortaggio Marcello Institute of Theoretical Physics
Faculty of Mathematics and Physics
Charles University in Prague
V Holešovickách 2
180 00 Prague 8
Czech Republic
Peik Eckehard Physikalisch-Technische Bundesanstalt
FB 4.4 Time and Frequency
Bundesallee 100
38116 Braunschweig
Germany
Podolsky Jiri Institute of Theoretical Physics
Faculty of Mathematics and Physics
Charles University in Prague
V Holešovickách 2
180 00 Prague 8
Czech Republic
Pravda Vojtech Institute of Theoretical Physics
Faculty of Mathematics and Physics
Charles University in Prague
V Holešovickách 2
180 00 Prague 8
Czech Republic
Rademaker Patricia ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany

Radu Eugen Laboratoire de Mathematiques et Physique Theorique
Universite Francois-Rabelais
Tours
France
Resch Andreas ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany
Ringwald Andreas Theory Group
DESY
Notkestraße 85
22603 Hamburg
Germany
Sarkar Sudipta Inter-University Centre for Astronomy and Astrophysics
IUCAA
Post Bag 4
Ganeshkhind
Pune University Campus
Pune 411 007
India
Schaffer Isabell ZARM
University of Bremen
Am Fallturm
20359 Bremen
Germany
schaffer@zarm.uni-bremen.de
Shimon Rubin Ben Gurion University
Be'er Sheva 84105
Israel
Shoom Andrey University of Alberta
CEB, 11322-89Ave,
Edmonton, Alberta,
T6G 2G7
Canada
Smolkin Misha Racah Institute of Physics
Hebrew University
Jerusalem 91904
Israel.
Stelea Cristian University of British Columbia
6224 Agricultural Road, Vancouver, BC
Canada
Tchrakian Tigran Department of Mathematical Physics
National University of Ireland
Maynooth
Ireland
Theisen Stefan Max-Planck-Institut für Gravitationsphysik
Albert-Einstein-Institut
Am MÜhlenberg 1
14476 Golm
Germany
Volkov Michael Laboratoire de Mathématiques et Physique Théorique
CNRS-UMR 6083,
Université de Tours
Parc de Grandmont
37200 Tours
France
Yoshino Hirotaka Department of Physics
University of Alberta
Edmonton, Alberta, T6G 2G7
Canada

Monday Tuesday Wednesday Thursday Friday
08:50 - 09:00 Welcome
09:00 - 09:50 Frolov Theisen Hartmann Cvetic Breitenlohner
09:50 - 10:40 Theisen Kleihaus Cvetic Kol Clement
10:40 - 11:10 coffee coffee coffee coffee coffee
11:10 - 12:00 Theisen Brihaye Cvetic Kol Clement
12:00 - 12:50 Kunz Volkov Krtous Kanti Tchrakian
12:50 - 15:00 lunch lunch lunch lunch lunch
15:00 - 15:50 Frolov Laemmerzahl
Kanti Discussion
15:50 - 16:40 Peik Adelberger Ringwald Discussion
16:40 - 17:10 coffee coffee excursion coffee coffee
17:10 - 18:00 Peik Adelberger Ringwald departure
18:00 - 18:50 2 short talks 2 short talks 2 short talks
19:00 social dinner dinner dinner dinner dinner