Multifunctional **Space**-**Time** Metasurfaces

**time**reconfigurable and environment-adaptive nonreciprocal wave controllers. Expand abstract.

**time**reconfigurable and environment-adaptive nonreciprocal wave controllers.

8/10 relevant

arXiv

Regularity estimates for nonlocal **space**-**time** master equations in bounded
domains

**space**-

**time**master equations $(\partial_t +L)^su = f$ in $\mathbb{R} \times \Omega$, where $L$ is an elliptic operator in divergence form, subject to homogeneous Dirichlet and Neumann boundary conditions. In particular, we establish the precise behavior of solutions near the boundary. Along the way, we prove a characterization of the correct intermediate parabolic H\"older

**spaces**in the spirit of Sergio Campanato.

10/10 relevant

arXiv

Hyperspectral terahertz microscopy via nonlinear ghost imaging

**space**-

**time**coupling, which is overcome by our technique. Expand abstract.

**Time**-Resolved Nonlinear Ghost Imaging and its ability to perform hyperspectral imaging in difficult-to-access wavelength regions, such as the Terahertz domain. We operate by combining nonlinear quadratic sparse generation and nonlinear detection in the Fourier plane. We demonstrate that traditional

**time**-slice approaches are prone to essential limitations in near-field imaging due to

**space**-

**time**coupling, which is overcome by our technique. As a proof-of-concept of our implementation, we show that we can provide experimental access to hyperspectral images completely unrecoverable through standard fixed-

**time**methods.

4/10 relevant

arXiv

Comment on "Comment on linear confinement of a scalar particle in a
G\"{o}del-type **space**-time"

**space**-

**time**with a cosmic string as a case particular ($k_{L}=0$) of [Vit\'{o}ria et al. Eur. Phys. J. C (2018) 78:44], in opposition what was stated in a recent paper published in this journal [F. Ahmed, Eur. Phys. J. C (2019) 79:682].

10/10 relevant

arXiv

A sparse occupancy model to quantify species interactions in **time** and **space**

**time**and

**space**to study niche partitioning. Expand abstract.

**Time**-dependent Occupancy Model for Camera Trap data (Tomcat), suited to estimate relative event densities in

**space**and

**time**. Tomcat allows to learn about the environmental requirements and daily activity patterns of species while accounting for imperfect detection. It further implements a sparse model that deals well will a large number of potentially highly correlated environmental variables. By integrating both spatial and temporal information, we extend the notation of overlap coefficient between species to

**time**and

**space**to study niche partitioning. We illustrate the power of Tomcat through an application to camera trap data of eight sympatrically occurring duiker species in the the savanna - rainforest ecotone in the Central African Republic and show that most species pairs show little overlap. Exceptions are those for which one species is very rare, likely as a result of direct competition.

7/10 relevant

bioRxiv

About toroidal soliton-particle of extremal **space**-**time** film

**space**-localized solution in toroidal coordinates with periodic dependence in

**time**is investigated. Expand abstract.

**space**-

**time**film is considered. Its

**space**-localized solution in toroidal coordinates with periodic dependence in

**time**is investigated. A field configuration having a form of the twisted lightlike soliton moving along the ring is considered. An iterative algorithm for obtaining the solution in the form of formal power series in one toroidal variable is proposed. It is discovered that the

**time**dependence in the toroidal solution has a deeply embedded character. Thus the full energy and angular momentum of the solution converge at

**space**infinity.

10/10 relevant

arXiv

Critical behavior for a semilinear parabolic equation with forcing term
depending of **time** and **space**

**time**and

**space**. we identify the critical exponent for this problem, which separates the nonexistence/existence of global-in-time solutions, and show the discontinuity... Expand abstract.

**time**behavior of the sign-changing solution of the inhomogeneous semilinear heat equation with a forcing term depending of

**time**and

**space**. we identify the critical exponent for this problem, which separates the nonexistence/existence of global-in-

**time**solutions, and show the discontinuity of this critical exponent at the point which the inhomogeneous term becomes independent of

**time**variable.

7/10 relevant

arXiv

Fast Rotating Relativistic Stars: Spectra and Stability without Approximation

**times**as well as the critical values for the onset of the secular (CFS) instability are presented. Expand abstract.

**space**-time. The study is based on the linearised version of Einstein's equations and via this approach the oscillation frequencies, the damping and growth

**times**as well as the critical values for the onset of the secular (CFS) instability are presented. The ultimate universal relations for asteroseismology are derived which can lead to relations involving the moment of inertia and Love numbers in an effort to uniquely constrain the equation of state via all possible observables. The results are important for all stages of neutron star's life but especially to nascent or post-merger cases.

4/10 relevant

arXiv

An exactly mass conserving **space**-**time** embedded-hybridized discontinuous
Galerkin method for the Navier-Stokes equations on moving domains

**space**-

**time**EHDG, EDG, and HDG methods. Expand abstract.

**space**-

**time**embedded-hybridized discontinuous Galerkin (EHDG) method for the Navier--Stokes equations on moving domains. This method uses a different hybridization compared to the

**space**-

**time**hybridized discontinuous Galerkin (HDG) method we presented previously in (Int. J. Numer. Meth. Fluids 89: 519--532, 2019). In the

**space**-

**time**EHDG method the velocity trace unknown is continuous while the pressure trace unknown is discontinuous across facets. In the

**space**-

**time**HDG method, all trace unknowns are discontinuous across facets. Alternatively, we present also a

**space**-

**time**embedded discontinuous Galerkin (EDG) method in which all trace unknowns are continuous across facets. The advantage of continuous trace unknowns is that the formulation has fewer global degrees-of-freedom for a given mesh than when using discontinuous trace unknowns. Nevertheless, the discrete velocity field obtained by the

**space**-

**time**EHDG and EDG methods, like the

**space**-

**time**HDG method, is exactly divergence-free, even on moving domains. However, only the

**space**-

**time**EHDG and HDG methods result in divergence-conforming velocity fields. An immediate consequence of this is that the

**space**-

**time**EHDG and HDG discretizations of the conservative form of the Navier--Stokes equations are energy stable. The

**space**-

**time**EDG method, on the other hand, requires a skew-symmetric formulation of the momentum advection term to be energy-stable. Numerical examples will demonstrate the differences in solution obtained by the

**space**-

**time**EHDG, EDG, and HDG methods.

10/10 relevant

arXiv

Convolutional Neural Networks for **Space**-**Time** Block Coding Recognition

**Space**-

**Time**Block coding(STBC) signal. Expand abstract.

**Space**-

**Time**Block coding(STBC) signal. The feature between Spatial Multiplexing (SM) and Alamouti (AL) signals is extracted via adapting convolutional neural networks after preprocessing the received sequence. Unlike other algorithms, this method does not require any prior information of channel coefficient, and noise power and, consequently, is well-suited for non-cooperative context. Results show that the proposed algorithm performs well even at a low signal to noise ratio (SNR).

10/10 relevant

arXiv