Publications (30)
Vacuum energy, the Casimir effect, and Newton's non-constant
Benjamin Koch, Christian Käding, Mario Pitschmann +1
We explore two hypotheses. First, the possibility that the quantum vacuum energy density of the Casimir effect contributes to a (local) gravitational vacuum energy density. Second,…
Acoustic Rabi oscillations between gravitational quantum states and impact on symmetron dark energy
Gunther Cronenberg, Philippe Brax, Hanno Filter +6
The standard model of cosmology provides a robust description of the evolution of the universe. Nevertheless, the small magnitude of the vacuum energy is troubling from a theoretic…
qBounce: First Measurement of the Neutron Electric Charge with a Ramsey-type GRS Experiment
Joachim Bosina, Hanno Filter, Jakob Micko +5
The qBounce collaboration built over the last years a new Ramsey-type Gravitational Resonance Spectroscopy (GRS) experiment. After commissioning between 2016 and 2018, the setup wa…
Dilaton Solutions for Laboratory Constraints and Lunar Laser Ranging
Philippe Brax, Hauke Fischer, Christian Käding +1
We derive approximate analytical solutions to the environment-dependent dilaton field theory equations in the presence of a one or two mirror system or a sphere. The one-dimensiona…
Equivalence of scalar-tensor theories and scale-dependent gravity
Philipp Neckam, Christian Käding, Benjamin Koch +4
We present a novel equivalence between scale-dependent gravity and scalar-tensor theories that have only a single scalar field with a canonical kinetic term in the Einstein frame a…
Density matrix formalism for interacting quantum fields
Christian Käding, Mario Pitschmann
We provide a description of interacting quantum fields in terms of density matrices for any occupation numbers in Fock space in a momentum basis. As a simple example, we focus on a…
Proof of Principle for Ramsey-type Gravity Resonance Spectroscopy with qBounce
René I. P. Sedmik, Joachim Bosina, Lukas Achatz +10
Ultracold neutrons (UCNs) are formidable probes in precision tests of gravity. With their negligible electric charge, dielectric moment, and polarizability they naturally evade som…
Gravity Resonance Spectroscopy and Dark Energy Symmetron Fields
Tobias Jenke, Joachim Bosina, Jakob Micko +3
Spectroscopic methods allow to measure energy differences with unrivaled precision. In the case of gravity resonance spectroscopy, energy differences of different gravitational sta…
Next generation design and prospects for CANNEX
René I. P. Sedmik, Mario Pitschmann
The Casimir And Non-Newtonian force EXperiment (CANNEX) implements the unique geometry of macroscopic plane parallel plates that guarantees an optimum sensitivity with respect to i…
Tests of Fundamental Quantum Mechanics and Dark Interactions with Low Energy Neutrons -- Extended Version
Stephan Sponar, Rene I. P. Sedmik, Mario Pitschmann +2
Among the known particles, the neutron takes a special position, as it provides experimental access to all four fundamental forces and a wide range of hypothetical interactions. De…
Electric dipole moment of the rho-meson
Mario Pitschmann, Chien-Yeah Seng, Michael J. Ramsey-Musolf +3
At an hadronic scale the effect of CP-violating interactions that typically appear in extensions of the Standard Model may be described by an effective Lagrangian, in which the ope…
Directly computing Wigner functions for open quantum systems
Nick Huggett, Christian Käding, Mario Pitschmann +1
The Wigner function is a well-known phase space distribution function with many applications in quantum mechanics. In this article, we consider an open quantum system consisting of…
Green's function analysis of the Neutron Lloyd interferometer
Christian Käding, Mario Pitschmann, Hartmut Abele
The neutron optical Lloyd interferometer can serve as a potent experiment for probing fundamental physics beyond the standard models of particles and cosmology. In this article, we…
Spectra of Neutron Wave Functions in Earth's Gravitational Field
Martin Suda, Manfried Faber, Joachim Bosina +5
The time evolution of a quantum wave packet in the linear gravity potential is known as Quantum Bouncing Ball. The qBounce collaboration recently observed such a system by dropping…
Quantum and thermal pressures from light scalar fields
Hauke Fischer, Christian Käding, Mario Pitschmann
Light scalar fields play a variety of roles in modern physics, especially in cosmology and modified theories of gravity. For this reason, there is a zoo of experiments actively try…
Distinguishing axions from generic light scalars using EDM and fifth-force experiments
Sonny Mantry, Mario Pitschmann, Michael J. Ramsey-Musolf
We derive electric dipole moment (EDM) constraints on possible new macroscopic time reversal and parity violating (TVPV) spin-dependent forces. These constraints are compared to th…
Differences between Axions and Generic Light Scalars in Laboratory Experiments
Sonny Mantry, Mario Pitschmann, Michael J. Ramsey-Musolf
It is well-known that electric dipole moment (EDM) constraints provide the most stringent bounds on axion-mediated macroscopic spin-dependent (SD) and time reversal and parity viol…
Nucleon tensor charges and electric dipole moments
Mario Pitschmann, Chien-Yeah Seng, Craig D. Roberts +1
A symmetry-preserving Dyson-Schwinger equation treatment of a vector-vector contact interaction is used to compute dressed-quark-core contributions to the nucleon -term and ten…
Search for environment-dependent dilatons
Hauke Fischer, Christian Käding, René I. P. Sedmik +3
The environment-dependent dilaton field is a well-motivated candidate for dark energy and naturally arises in the strong coupling limit of string theory. In this article, we presen…
Schrödinger Equation for a Non-Relativistic Particle in a Gravitational Field confined by Two Vibrating Mirrors
Mario Pitschmann, Hartmut Abele
We derive approximate analytical solutions for a particle in a homogenous gravitational field and confined between two independently vibrating mirrors. This constitutes an extensio…
Search for dark energy with neutron interferometry
Hauke Fischer, Christian Käding, Hartmut Lemmel +2
We use previously obtained experimental results by neutron interferometry to effectively constrain the parameter space of several prominent dark energy models. This investigation e…
A new method for directly computing reduced density matrices
Christian Käding, Mario Pitschmann
We demonstrate the power of a first principle-based and practicable method that allows for the perturbative computation of reduced density matrix elements of an open quantum system…
Exact Solutions to Non-Linear Symmetron Theory II: One and Two Mirror Systems
Mario Pitschmann
We derive the exact analytical solutions to the symmetron field theory equations in the presence of a one or two mirror system in the case of a spontaneously broken phase in vacuum…
Shape vibrations of topological fermions
Manfried Faber, Alexander Kobushkin, Mario Pitschmann
We analyze the model of topological fermions, where charged fermions are treated as topological solitons. We discuss vibrations of soliton shapes. It is shown that depending on the…
Density matrices in quantum field theory: Non-Markovianity, path integrals and master equations
Christian Käding, Mario Pitschmann
Density matrices are powerful mathematical tools for the description of closed and open quantum systems. Recently, methods for the direct computation of density matrix elements in…
Dilaton-induced open quantum dynamics
Christian Käding, Mario Pitschmann, Caroline Voith
In modern cosmology, scalar fields with screening mechanisms are often used as explanations for phenomena like dark energy or dark matter. Amongst a zoo of models, the environment…
Force metrology with plane parallel plates: Final design review and outlook
Hamid Haghmoradi, Hauke Fischer, Alessandro Bertolini +5
During the past few decades, abundant evidence for physics beyond the two standard models of particle physics and cosmology was found. Yet, we are tapping into the dark regarding o…
Exact Solutions to Non-Linear Symmetron Theory: One and Two Mirror Systems
Philippe Brax, Mario Pitschmann
We derive the exact analytical solutions to the symmetron field theory equations in the presence of a one or two mirror system. The one dimensional equations of motion are integrat…
Gravity Resonance Spectroscopy and Einstein-Cartan Gravity
Hartmut Abele, Andrei Ivanov, Tobias Jenke +2
The qBounce experiment offers a new way of looking at gravitation based on quantum interference. An ultracold neutron is reflected in well-defined quantum states in the gravity pot…
Screened Scalar Fields in the Laboratory and the Solar System
Hauke Fischer, Christian Käding, Mario Pitschmann
The last few decades have provided abundant evidence for physics beyond the two standard models of particle physics and cosmology. As is now known, the by far largest part of our u…