10 citations · 27 across the 26 of their papers we have counts for
36 papers
Detecting Einstein metrics on products of spheres
Anna Siffert
On \[ S^5\times S^2,\qquad S^5\times S^3,\qquad S^5\times S^4,\qquad S^7\times S^2, \] we construct infinitely many pairwise non-isometric real-analytic Einstein metrics. After dis…
New Homogeneous Einstein Metrics from Detection
Anna Siffert
We use a detection method for invariant Einstein equations to construct and distinguish asymmetric homogeneous Einstein metrics on several families of compact homogeneous spaces. T…
Quantized Einstein Metrics on with -Symmetry
Anna Siffert
We prove that the standard cohomogeneity-one action of \(SU(3)\) on \(S^7\), with principal orbit the Wallach flag manifold \(SU(3)/T^2\), admits infinitely many invariant Einstein…
Response Geometry for Einstein metrics
Anna Siffert
We develop a response geometry for smooth parameterized families of Einstein metrics equipped with canonical probe data. The differential of the probe observations defines a respon…
Einstein Metrics and Equivariant Harmonic Maps: The Einstein Detection Principle
Anna Siffert
We develop a new analytical framework for the local deformation theory of compact cohomogeneity-one Einstein metrics. The framework combines an intrinsic reformulation of the Einst…
The Nullity of a Family of Proper Biharmonic Maps via Elliptic Curves
Anna Siffert
We prove a conjecture of Montaldo, Oniciuc and Ratto concerning the nullity of a family of proper biharmonic maps from the flat two-torus to the round two-sphere. The proof reveals…
A framework for producing harmonic maps
Volker Branding, Anna Siffert
We present a general framework for producing families of harmonic maps from the unit ball into the Euclidean sphere starting from a fixed harmonic map. In particular, our analysis…
Construction of harmonic maps between cohomogeneity one manifolds
Anna Siffert
We construct equivariant harmonic maps between cohomogeneity one manifolds.
The Initial Value Problem for Harmonic maps of Cohomogeneity One manifolds
Anna Siffert
We set up and solve the initial value problem for equivariant harmonic maps of cohomogeneity one manifolds, i.e. we show the local existence of a harmonic map in the neighborhood o…
Stable proper biharmonic maps in Euclidean spheres
Volker Branding, Anna Siffert
We construct an explicit family of stable proper weak biharmonic maps from the unit ball , , to Euclidean spheres. To the best of the authors knowledge this is the fi…
On the stability of the generalized equator map
Volker Branding, Anna Siffert
The energy, the -energy ( with ) and the extrinsic -energy () for maps between Riemannian manifolds are central objects in the geomet…
A family of triharmonic maps to spheres in all dimensions greater than two
Volker Branding, Anna Siffert
We present a construction method for triharmonic maps to spheres. In particular, we show that for any with there exists a triharmonic map from $\mathbb{R…
Magnetic Steklov problem on surfaces
Mihajlo Cekić, Anna Siffert
The magnetic Dirichlet-to-Neumann map encodes the voltage-to-current measurements under the influence of a magnetic field. In the case of surfaces, we provide precise spectral asym…
Construction of -harmonic submanifolds
José Miguel Balado-Alves, Anna Siffert
We provide a construction method for biharmonic submanifolds in cohomogeneity one manifolds. In particular, we give new examples of biharmonic submanifolds and study the normal ind…
Global eigenfamilies on closed manifolds
Oskar Riedler, Anna Siffert
We study globally defined -eigenfamilies on closed Riemannian manifolds. Among others, we provide (non-)existence results for such eigenfamilies, examine their topological p…
Infinite families of harmonic self-maps of ellipsoids in all dimensions
Volker Branding, Anna Siffert
We prove that for given , , and each with \begin{align*} a^2<4d (d+k-2)(k-2)^{-2} \end{align*} the ellipsoid $E_a:=\{…
On p-harmonic self-maps of spheres
Volker Branding, Anna Siffert
In this manuscript we study rotationally -harmonic maps between spheres. We prove that for given, there exist infinitely many -harmonic self-maps of $\mathbb…
A family of free boundary minimal surfaces in the unit ball
Anna Siffert, Jan Wuzyk
Using equivariant differential geometry, we provide a family of free boundary minimal surfaces in the unit ball.
On the equivariant stability of harmonic self-maps of cohomogeneity one manifolds
Volker Branding, Anna Siffert
The systematic study of harmonic self-maps on cohomogeneity one manifolds has recently been initiated by Püttmann and the second named author in \cite{MR4000241}. In this article w…
Explicit proper p-harmonic functions on the Riemannian symmetric spaces SU(n)/SO(n), Sp(n)/U(n), SO(2n)/U(n), SU(2n)/Sp(n)
Sigmundur Gudmundsson, Anna Siffert, Marko Sobak
In this work we construct explicit complex-valued p-harmonic functions on the compact Riemannian symmetric spaces SU(n)/SO(n), Sp(n)/U(n), SO(2n)/U(n), SU(2n)/Sp(n). We also descri…
Explicit p-harmonic functions on rank-one Lie groups of Iwasawa type
Sigmundur Gudmundsson, Anna Siffert, Marko Sobak
We construct explicit proper p-harmonic functions on rank-one Lie groups of Iwasawa type. This class of Lie groups includes many classical Riemannian manifolds such as the rank-one…
Proper -harmonic functions on the Thurston geometries
Sigmundur Gudmundsson, Anna Siffert
For any positive natural number we construct new explicit proper -harmonic functions on the celebrated -dimensional Thurston geometries $\Sol$, $\Nil$, $\SL2$, $\H…
Handle attachment and the normalized first eigenvalue
Henrik Matthiesen, Anna Siffert
We show that the first eigenvalue of a closed Riemannian surface normalized by the area can be strictly increased by attaching a cylinder or a cross cap. As a consequence we obtain…
Sharp asymptotics of the first eigenvalue on some degenerating surfaces
Henrik Matthiesen, Anna Siffert
We study sharp asymptotics of the first eigenvalue on Riemannian surfaces obtained from a fixed Riemannian surface by attaching a collapsing flat handle or cross cap to it. Through…