arXiv subjects

S. Hossenfelder

Publications and source records attributed to S. Hossenfelder.

27 records · Page 2Linked to original sources

arXiv2006

Anti-Gravitation

The possibility of a symmetry between gravitating and anti-gravitating particles is examined. The properties of the anti-gravitating fields are defined by their behavior under general diffeomorphisms. The equations of motion and the conserved canonical currents are derived, and it is shown that the kinetic energy remains positive whereas the new fields can make a negative contribution to the source term of Einstein's field equations. The interaction between the two types of fields is naturally suppressed by the Planck scale.

gr-qc↗

arXiv2006

Self-consistency in Theories with a Minimal Length

The aim of this paper is to clarify the relation between three different approaches of theories with a minimal length scale: A modification of the Lorentz-group in the 'Deformed Special Relativity', theories with a 'Generalized Uncertainty Principle' and those with 'Modified Dispersion Relations'. It is shown that the first two are equivalent, how they can be translated into each other, and how the third can be obtained from them. An adequate theory with a minimal length scale requires all three features to be present.

hep-th↗

arXiv2005

News about TeV-scale Black Holes

Collider produced black holes are the most exciting prediction from models with large extra dimensions. These black holes exist in an extreme region, in which gravity meets quantum field theory, particle physics, and thermodynamics. An investigation of the formation and decay processes can therefore provide us with important insights about the underlying theory and open a window to the understanding of Physics at the Planck scale. The production and the evaporation of TeV-scale black holes yields distinct signatures that have been examined closely during the last years, with analytical approaches as well as by use of numerical simulations. I present new results for the LHC, which take into account that, instead of a final decay, a black hole remnant can be left. This is a summary of the talk given at the Quark Matter 2005, Budapest, Hungary, Aug. 2005.

hep-ph↗

arXiv2004

Suppressed Black Hole Production from Minimal Length

Large extra dimensions lower the Planck scale to values soon accessible. Motivated by string theory, the models of large extra dimensions predict a vast number of new effects in the energy range of the lowered Planck scale, among them the production of TeV-mass black holes. But not only is the Planck scale the energy scale at which effects of modified gravity become important. String theory as well as noncommutative quantum mechanics suggest that the Planck length acts a a minimal length in nature, providing a natural ultraviolet cutoff and a limit to the possible resolution of spacetime. The minimal length effects thus become important in the same energy range in which the black holes are expected to form. In this paper we examine the influence of the minimal length on the expected production rate of the black holes.

hep-th↗

arXiv2004

Signatures of Large Extra Dimensions

String theory suggests modifications of our spacetime such as extra dimensions and the existence of a mininal length scale. In models with addidional dimensions, the Planck scale can be lowered to values accessible by future colliders. Effective theories which extend beyond the standart-model by including extra dimensions and a minimal length allow computation of observables and can be used to make testable predictions. Expected effects that arise within these models are the production of gravitons and black holes. Furthermore, the Planck-length is a lower bound to the possible resolution of spacetime which might be reached soon.

hep-ph↗

arXiv2004

Signatures of a minimal length scale in high precision experiments

We discuss modifications of the gyromagnetic moment of electrons and muons due to a minimal length scale combined with a modified fundamental scale $M_f$. First-order deviations from the theoretical standard model value for $g-2$ due to these String Theory-motivated effects are derived. A constraint of $M_f>577 GeV$ for the new fundamental scale is given.

hep-ph↗

arXiv2003

Probing the minimal length scale by precision tests of the muon g-2

Modifications of the gyromagnetic moment of electrons and muons due to a minimal length scale combined with a modified fundamental scale M_f are explored. Deviations from the theoretical Standard Model value for g-2 are derived. Constraints for the fundamental scale M_f are given.

hep-ph↗

arXiv2003

Signatures in the Planck Regime

String theory suggests the existence of a minimum length scale. An exciting quantum mechanical implication of this feature is a modification of the uncertainty principle. In contrast to the conventional approach, this generalised uncertainty principle does not allow to resolve space time distances below the Planck length. In models with extra dimensions, which are also motivated by string theory, the Planck scale can be lowered to values accessible by ultra high energetic cosmic rays (UHECRs) and by future colliders, i.e. $M_f\approx$ 1 TeV. It is demonstrated that in this novel scenario, short distance physics below $1/M_f$ is completely cloaked by the uncertainty principle. Therefore, Planckian effects could be the final physics discovery at future colliders and in UHECRs. As an application, we predict the modifications to the $e^+e^- \to f^+f^-$ cross-sections.

hep-th↗

arXiv2002

Suppression of High-P_T Jets as a Signal for Large Extra Dimensions and New Estimates of Lifetimes for Meta stable Micro Black Holes -From the Early Universe to Future Colliders

We address the production of black holes at LHC in space times with compactified space-like large extra dimensions (LXD). Final state black hole production leads to suppression of high-P_T jets, i.e. a sharp cut-off in the cross section for pp->jet+X. This signal is compared to the jet plus missing energy signature due to graviton production in the final state as proposed by the ATLAS collaboration. Time evolution and lifetimes of the newly created black holes are calculated based on the microcanonical formalism. It is demonstrated that previous lifetime estimates of micro black holes have been dramatically underestimated. The creation of a large number of quasi-stable black holes is predicted with life times beyond hundred fm/c at LHC. Medium modifications of the black holes evaporation rate due to the quark gluon plasma in relativistic heavy ion collisions as well as provided by the cosmic fluid in the early universe are studied.

hep-ph↗