## Seminars

### Winter term 2019/20

### Quantum phase-field: from de Broglie–Bohm double solution program to doublon networks

Abstract: We study different variants of linear and non-linear field equations, so-called ‘phase-field’ equations, in application to the de Broglie–Bohm double solution program. This defines a framework in which elementary particles are described by peaked non-linear wave solutions moving by the quidance of a linear pilot wave. First, we consider the phase-field order parameter as a phase for the pilot wave, second as the pilot wave, third as a moving soliton which describes the particle. In the last case, we intoduce a superwave which amplitude is responsible for the particle moving in accordance to the de Broglie–Bohm theory. Lax pairs for the coupled problems are found in order to discover the phase-field equations and to draw analogies to the de Broglie–Bohm double solution program. Finally, doublons in 1+1 dimensions are constructed as self similar solutions of a non-linear phase-field equation. The doublons set the frame for a Schrödinger type linear wave equation determining the energetics of the coupled system. Applying a conservation constraint and using general symmetry considerations the doublons are arranged as a network in 1+1+2 dimensions where nodes are interpreted as elementary particles.

### Quantum creation of a universe-antiuniverse pair

Abstract: The creation of two universes, one contracting and another expanding, filled with matter can also be interpreted as the creation of two expanding universes, one of them filled with matter and the other filled with antimatter, forming a universe-antiuniverse pair. In that case, the total amount of matter and antimatter in the two universes is completely balanced, restoring the (apparent) matter-antimatter asymmetry observed in each single universe. Furthermore, the creation of universes in pairs would entail observational consequences, perhaps distinguishable, in the properties of the CMB of a universe like ours, making testable the whole multiverse proposal.

### Spatial curvature of cosmic structures

Abstract: Curvature of spatial hyper-surfaces is usually considered in the context of globally homogeneous cosmological models, however it can also play a non-negligible role below the scale of homogeneity. Relativistic Lagrangian perturbations allow us to get insight into mildly non-linear stages of structure formation, substantially exceeding the standard Eulerian regime. In my talk, I will mainly focus on the spatial curvature estimates utilizing the Relativistic Zel'dovich approximation which is the first order solution to Einstein equations in Lagrangian form. Several theoretical and numerical results will be presented including the value of scalar curvature and averaged scalar curvature at the turnaround epoch for a wide set of initial conditions. Potential observational consequences will be put into perspective.

Date | Time | Speaker | Topic | Room |
---|---|---|---|---|

October 8, 2019 | 12:00 |
Leonardo Chataignier (Uni Cologne) |
Conference report | Konferenzraum 1 (Neubau) |

October 15 | 12:00 |
Ingo Steinbach (Ruhr-Universität Bochum) |
Quantum phase-field: from de Broglie–Bohm double solution program to doublon networks | Konferenzraum 1 (Neubau) |

October 22 | 12:00 |
Salvador Robles-Pérez (Estación Ecológica de Biocosmología de Medellín (Spain)) |
Quantum creation of a universe-antiuniverse pair | Konferenzraum 1 (Neubau) |

November 19 | 12:00 |
Jan J. Ostrowski (Narodowe Centrum Badań Jądrowych, Warsaw) |
Spatial curvature of cosmic structures | Konferenzraum 1 (Neubau) |

## Past seminars

Summer term 2019

Winter term 2018/19

Summer term 2018

Winter term 2017/18

Summer term 2017

Winter term 2016/17

Summer term 2016

Winter term 2015/16

Summer term 2015

Winter term 2014/15

Summer term 2014

Winter term 2013/14

Summer term 2013

Winter term 2012/13

Summer term 2012

Winter term 2011/12

Summer term 2011

Winter term 2010/11

Summer term 2010

Winter term 2009/10

Summer term 2009

Winter term 2008/09

Summer term 2008

Winter term 2007/08

Summer term 2007

Winter term 2006/07

Summer term 2006

Summer term 2005

Winter term 2004/05

Summer term 2004

Winter term 2003/04

Summer term 2003