arXiv research

Study limits of quasi-local angular momentum at infinity of gravitating systems.

We describe an $A_\infty$-quasi-equivalence of dg-categories between the first authors' $\mathcal{P}_{\mathcal{A}}$ ---the category of category of prefect $A^0$-modules with flat $\Z$-connection, corresponding to the de Rham dga $\mathcal{A}$ of a compact manifold $M$--- and the dg-category of \emph{infinity-local syst…

The paper examines mass aspects at future null infinity and limits of quasilocal mass.

We prove a categorified Poincaré lemma using $\mathsf{A}_\infty$-structures.

Computes quasi-local mass at null infinity using Bondi-Sachs coordinates.

Local mass at null infinity confirmed for Vaidya spacetime.

Categorifies Chern-Weil theory for infinite local systems.

Researchers define and evaluate quasi-local mass near axially symmetric null infinity.

Algorithm describes Fourier transform of Stokes data at infinity.

Researchers calculate quasi-local mass on unit spheres at infinity.

Study of Gordian graphs' behavior at infinity for various local moves.

Study the fractional Yamabe problem on locally flat conformal infinities of Poincaré-Einstein manifolds.

Researchers calculate limits of angular momentum and center-of-mass at null infinity.

For a spacelike 2-surface in spacetime, we propose a new definition of quasi-local angular momentum and quasi-local center of mass, as an element in the dual space of the Lie algebra of the Lorentz group. Together with previous defined quasi-local energy-momentum, this completes the definition of conserved quantities i…

New approach to Lagrangian field theories using pro-finite structures and L-infinity algebras.

The paper shows deep neural networks have no bad local minima and no diverging paths to infinity.

Ecker's and Huisken's quantities agree for ancient mean curvature flows.

Study Cheeger constant and Yamabe type for ALH manifolds.

We give a necessary condition for a meromorphic function in several variables to give rise to a Milnor fibration of the local link (respectively of the link at infinity). In the case of two variables we give some necessary and sufficient conditions for the local link (respectively the link at infinity) to be fibred.

We identify the Variational Principle governing inifinity-Harmonic maps, that is solutions to the Infinity-Laplacian. The system was first derived in the limit of the p-Laplacian as p->inifinity in [K2] and is recently studied in [K3]. Here we show that it is the "Euler-Lagrange PDE" of vector-valued Calculus of Variat…

Paper addresses LSTM stability for thermal systems using infinity-norm.

Defines vector fields and differential forms on local C-infinity-ringed spaces.

Modeling financial systemic risk with optimal control theory for stability.

Unique solutions found for wave-like decaying null infinity equations.

Study geodesics in conformally compact manifolds, showing smoothness and asymptotic behavior.

We modify previous quasi-local mass definition. The new definition provides expressions of the quasi-local energy, the quasi-local linear momentum and the quasi-local mass. And they are equal to the ADM expressions at spatial infinity. Moreover, the new quasi-local energy has the positivity property.

We construct examples of smooth 4-dimensional manifolds M supporting a locally CAT(0)-metric, whose universal cover X satisfy Hruska's isolated flats condition, and contain 2-dimensional flats F with the property that the boundary at infinity of F defines a nontrivial knot in the boundary at infinity of X. As a consequ…

We initiate the study of the spherically symmetric Einstein-Klein-Gordon system in the presence of a negative cosmological constant, a model appearing frequently in the context of high-energy physics. Due to the lack of global hyperbolicity of the solutions, the natural formulation of dynamics is that of an initial bou…

The paper proves hyperbolic groups are semistable and their boundaries are linearly connected.

In this paper, we study the limiting behavior of the Brown-York mass and Hawking mass along nearly round surfaces at infinity of an asymptotically flat manifold. Nearly round surfaces can be defined in an intrinsic way. Our results show that the ADM mass of an asymptotically flat 3-manifold can be approximated by some …

Paper proves trapped surface formation for EMCSF system without symmetry assumptions.

New theorem: Spaces with coaxial homeomorphisms are 2-equivalent to trees.

We announce new results concerning the asymptotic behavior of the Betti numbers of higher rank locally symmetric spaces as their volumes tend to infinity. Our main theorem is a uniform version of the Lück Approximation Theorem \cite{luck}, which is much stronger than the linear upper bounds on Betti numbers given by Gr…

We describe how to compute topological objects associated to a polynomial map of several complex variables with isolated singularities. These objects are: the affine critical values, the affine Milnor numbers for all irregular fibers, the critical values at infinity, and the Milnor numbers at infinity for all irregular…

Study on scalar curvature decay on non-compact manifolds linked at infinity.

Modified condition proves no positive scalar curvature for enlargeable manifolds.

We argue that some classical local geometries are of infinity origin, i.e. their smooth formal germs are (homotopy) representations of cofibrant (di)operads in spaces concentrated in degree zero. In particular, they admit natural infinity generalizations when one considers homotopy representations of that (di)operads i…

New obstruction found for smoothability of certain 4-manifolds.

One of the main purposes of this paper is to prove that on a complete Kähler manifold of dimension $m$, if the holomorphic bisectional curvature is bounded from below by -1 and the minimum spectrum $λ_1(M) \ge m^2$, then it must either be connected at infinity or diffeomorphic to $\Bbb R \times N$, where $N$ is a compa…

Study of gravitational radiation using quasi-local energy.

We give a topological model for a polynomial map from $\C^n$ to $\C$ in the neighborhood of a fiber with isolated singularities. This is motivated out of the ``unfolding of links'' described earlier by the first author and Lee Rudolph. The topological model gives a useful encoding of the local and global monodromy for …

In this paper we use continuous family of multisections of the moduli space of pseudo holomorphic discs to partially improve, in the case of real coefficient, the construction of Lagrangian Floer cohomology of which the author developed jointly with Oh-Ohta-Ono. Namely we associate cyclically symmetric filtered A infin…

We define a generalized mass for asymptotically flat manifolds using some higher order symmetric function of the curvature tensor. This mass is non-negative when the manifold is locally conformally flat and the $σ_k$ curvature vanishes at infinity. In addition, with the above assumptions, if the mass is zero, then, nea…

In this paper we continue an earlier study of ends non-compact manifolds. The over-arching goal is to investigate and obtain generalizations of Siebenmann's famous collaring theorem that may be applied to manifolds having non-stable fundamental group systems at infinity. In this paper we show that, for manifolds with c…

Formulae track evolution of angular momentum and center of mass at null infinity.

We continue our study of ends non-compact manifolds. The over-arching aim is to provide an appropriate generalization of Siebenmann's famous collaring theorem that applies to manifolds having non-stable fundamental group systems at infinity. In this paper a primary goal is finally achieved; namely, a complete character…

We show that holographic renormalization of relativistic gravity in asymptotically Lifshitz spacetimes naturally reproduces the structure of gravity with anisotropic scaling: The holographic counterterms induced near anisotropic infinity take the form of the action for gravity at a Lifshitz point, with the appropriate …

We study constant mean curvature 1/2 surfaces in H2xR that admit a compactification of the mean curvature operator. We show that a particular family of complete entire graphs over H2 admits a structure of infinite dimensional manifold with local control on the behaviors at infinity. These graphs also appear to have a h…