Johannes Ebert
YOU?
Author Swipe
View article: Cancellation properties for exotic $4$-dimensional positive scalar curvature metrics
Cancellation properties for exotic $4$-dimensional positive scalar curvature metrics Open
Ruberman constructed families $\{g_n\vert n \in \mathbb{N}\} \subset \mathcal{R}^+ (M)$ of metrics of positive scalar curvature on certain $4$-manifolds which are concordant but lie in different path components of $\mathcal{R}^+ (M)$. We p…
View article: Analysis of the energy exchange between coupled subsystems by means of the divergence in the vibratory energy field
Analysis of the energy exchange between coupled subsystems by means of the divergence in the vibratory energy field Open
One way of analysing a system with respect to its acoustical properties is to take a look at energetic phenomena and behaviours. A method widely used is the description of the energy flow in terms of acoustic intensities in both the struct…
View article: Tautological classes and higher signatures
Tautological classes and higher signatures Open
For a bundle of oriented closed smooth $n$-manifolds $π: E \to X$, the tautological class $κ_{\mathcal{L}_k} (E) \in H^{4k-n}(X;\mathbb{Q})$ is defined by fibre integration of the Hirzebruch class $\mathcal{L}_k (T_v E)$ of the vertical ta…
View article: Some rational homology computations for diffeomorphisms of odd‐dimensional manifolds
Some rational homology computations for diffeomorphisms of odd‐dimensional manifolds Open
We calculate the rational cohomology of the classifying space of the diffeomorphism group of the manifolds , for large and , up to degree . The answer is that it is a free graded commutative algebra on an appropriate set of Miller–Morita–M…
View article: E-TEST: a compact low-frequency isolator for a large cryogenic mirror
E-TEST: a compact low-frequency isolator for a large cryogenic mirror Open
To achieve the expected level of sensitivity of third-generation gravitational-wave (GW) observatories, more accurate and sensitive instruments than those of the second generation must be used to reduce all sources of noises. Amongst them,…
View article: Comparative Assessment of the Size-of-Source Effect in Middle- and Long-Wavelength Infrared Camera
Comparative Assessment of the Size-of-Source Effect in Middle- and Long-Wavelength Infrared Camera Open
Current radiometric calibration procedures for thermal imaging cameras are usually performed for a single calibration geometry. The uncertainty estimated from such a procedure only represents the calibration scenario and does not account f…
View article: Diffeomorphisms of odd-dimensional discs, glued into a manifold
Diffeomorphisms of odd-dimensional discs, glued into a manifold Open
For a compact $(2n+1)$-dimensional smooth manifold, let $μ_M : B Diff_\partial (D^{2n+1}) \to B Diff (M)$ be the map that is defined by extending diffeomorphisms on an embedded disc by the identity. By a classical result of Farrell and Hsi…
View article: Q-Band LEO Earth Observation Data Downlink: Radiowave Propagation and System Performance
Q-Band LEO Earth Observation Data Downlink: Radiowave Propagation and System Performance Open
Earth Exploration Satellite Service (EESS) systems gather data about the Earth and its natural phenomena. Frequency bands traditionally employed by high-rate telemetry to download data from the satellite to the ground station, such as the …
View article: Issue Information
Issue Information Open
The effect of a preparation containing glycocholic acid and/or agitation
View article: On the homotopy type of the space of metrics of positive scalar curvature
On the homotopy type of the space of metrics of positive scalar curvature Open
Let $M^d$ be a simply connected spin manifold of dimension $d \geq 5$ admitting Riemannian metrics of positive scalar curvature. Denote by $\mathcal{R}^+(M^d)$ the space of such metrics on $M^d$. We show that $\mathcal{R}^+(M^d)$ is homoto…
View article: The positive scalar curvature cobordism category
The positive scalar curvature cobordism category Open
We prove that many spaces of positive scalar curvature metrics have the homotopy type of infinite loop spaces. Our result in particular applies to the path component of the round metric inside $\mathcal{R}^+ (S^d)$ if $d \geq 6$. To achiev…
View article: Multi-User Detection Performance Demonstrator for Realistic High Throughput Satellite Systems
Multi-User Detection Performance Demonstrator for Realistic High Throughput Satellite Systems Open
Multi-beam satellite systems gain capacity from frequency reuse in the forward link, but they suffer from inter-system interference problems. Multi-user detection (MUD) is an advanced interference mitigation technique applied at the user t…
View article: Mutual Information Analysis Of Frequency Packing Schemes In Multi-Beam Satellite Systems
Mutual Information Analysis Of Frequency Packing Schemes In Multi-Beam Satellite Systems Open
This paper analyzes frequency packing schemes applied to multibeam satellite systems. In order to simulate a realistic scenario we have taken into account the presence of co-channel interference and spectrum limitations. The results show t…
View article: System Performance Of An Advanced Multi-User Detection Technique For High Throughput Satellite Systems
System Performance Of An Advanced Multi-User Detection Technique For High Throughput Satellite Systems Open
The growing demand for high rate broadband satellite services delivered through multi-spot beam systems pushes more and more for spectrum re-usage over the coverage. In this context, due to the non-perfect isolation among the beams, the am…