Primordial Black Holes - Formation and Observational Constraints

• Florian Kühnel

Room: Bldg. 2a, SR 2

Primordial Black Holes from Inflation and Their Implications

• Kyohei Mukaida

Room: Bldg. 2a, SR 2

Sourced density perturbations and gravitational waves (GW) from inflation, and GW signatures of Primordial Black Holes

• Marco Peloso

Room: Bldg. 2a, SR 2

Gravitational waves and primordial black holes from cosmic inflation

• Valerie Domcke

Room: Bldg. 2a, SR 2

Primordial black holes: Linking Microphysics and Macrophysics

• Bernard Carr

Room: Bldg. 2a, SR 2 Black holes could span 60 decades of mass - from the Planck scale (10-5g) to the cosmological scale (1022Mo) - and therefore provide an important link between microphysics and macrophysics. In the macroscopic domain, attention has recently turned to the possibility that primordial black holes (i.e. those formed in the early universe) could provide the dark matter or the black-hole mergers detected by LIGO or even some features of cosmic structure. In the microscopic domain, primordial black holes lighter than the Earth would have a Hawking temperature exceeding that of the cosmic microwave background, so that quantum effects are important. Such quantum black holes span the lower 30 decades of mass and provide a unique probe of the early universe and high energy physics. The micro-macro link is most striking at the Planck scale, with Planckian black holes likely to play a key role in quantum gravity. This raises the question of what happens to relativity theory as one approaches the Planck scale from above (eg. the Schwarzschild radius) and to quantum theory as one approaches it from below (eg. the Compton radius). It is argued that there should be a smooth transition between these two scales, corresponding to a unified Compton-Schwarzschild expression. In this case, there may also be a link between elementary particles and sub-Planckian black holes. It is also argued that the duality between the Compton and Schwarzschild scales should be maintained if the number of spatial dimensions increases, which has important implications for the observability of black holes in accelerators.

Quantum Tests of Gravity: State of the Play, Prospects and Experimental Challenges

• Markus Aspelmeyer

Room: Bldg. 2a, SR 2

Quantum Superposition of Massive Objects and the Quantization of Gravity

• Alessio Belenchia

Room: Bldg. 2a, SR 2

Transferring two massive mirrors into a single quantum object

• Roman Schnabel

Room: Bldg. 2a, SR 2 When a single quantum object decays into two, the new objects show quantum entanglement. For the experimental demonstration of this entanglement, a large number of identical decays need to be available and specific measurements on the new objects performed. This talk considers the opposite direction of evolution and describes an experiment, in which two laser mirrors that are suspended as pendulums might be transferred to a single quantum object. The unification goes hand in hand with the mirrors losing the realism of their individual positions and momenta. Here, the definition of (local) realism is according to the 1935-discussion by Einstein, Podolsky and Rosen. In the envisioned experiment, the two mirrors will have masses of about 100g and are located close to each other such that they sense the mutual gravitational potential. If successful the experiment might be a probe system for Newtonian quantum gravity theories.

Is the Moon there when nobody looks?

• Serge Reynaud

Room: Bldg. 2a, SR 2

Quantum Coherences with Gravity

• Myungshik Kim (Imperial College London)

Room: Bldg. 2a, SR 2

Evidence for the history of cosmic expansion

• Matthias Bartelmann

Room: Bldg. 2a, SR 2 The cosmic expansion function, quantifying how the relative cosmic expansion rate developed in cosmic history, is one of two central and (almost) directly observable properties of our Universe. From a theoretical point of view, the expansion function is determined by the time evolution of all forms of matter and energy density in the Universe. Empirically, it enters into all distance measures and into the growth function describing the evolution of cosmic structures. I will first summarize the empirical information available on the expansion function and then show that the expansion function is tightly contrained without the need to specify any cosmological model. Adopting a metric theory of gravity and the usual symmetries of spatial isotropy and homogeneity suffice to determine the expansion function quite precisely. With little further assumptions, also the growth function is empirically tightly constrained. Such empirical limits on these two functions which are independent of any particular cosmological model, are to a large degree also valid for alternative theories of gravity.

de Sitter Space and String Theory

• Alexander Westphal

Room: Bldg. 2a, SR 2

dS Swampland conjectures and KKLT

• Arthur Hebecker

Room: Bldg. 2a, SR 2

Secrets of de Sitter and phenomenological implications

• Georgi Dvali

Room: Bldg. 2a, SR 2