This paper answers a question of Burns, Karrass and Solitar by giving examples of knot and link groups which are not subgroup-separable. For instance, it is shown that the fundamental group of the square knot complement is not subgroup separable. Let L denote the fundamental group of the link consisting of a chain of 4 circles. It is shown that L is not subgroup separable. Furthermore, it is sh...

Coalgebra-Galois extensions generalise Hopf-Galois extensions, which can be viewed as non-commutative torsors. In this paper it is analysed when a coalgebra-Galois extension is a separable, split, or strongly separable extension.

This paper proposes an N stage "non-separable" two-dimensional (2D) wavelet transform (WT) for lossless / lossy unified coding of digital images. The proposed method achieves better coding performance especially at high bit rate since it has fewer rounding operations. We convert the conventional "separable" 2D WT into "non-separable" one without changing its frequency characteristics so that th...

We discuss a few situations related to non separable correlations in multiterminal hybrid structures. We show that the existence of such correlations can modify the strength of the gap of the superconductor. We discuss linear combinations of non local Cooper pairs. We discuss a possible transport experiment intended to probe non separable correlations. The models are worked out at the heuristic...

In the main text, we focus on the case of preferences that are separable between non-housing and housing consumption streams {ct(s)} and {ht(s)}. Here we extend the analysis to the case of non-separable preferences. We use two approaches to derive testable implications from the model. The first approach links our model to the traditional risk-sharing tests based on linear consumption growth reg...

Cardinal invariants related to sequential separability of generalized Cantor cubes 2κ, introduced by M. Matveev, are studied here. In particular, it is shown that the following assertions are relatively consistent with ZFC: (1) 2ω1 is sequentially separable, yet there is a countable dense subset of 2ω1 containing no non-trivial convergent subsequence, (2) 2ω1 is not sequentially separable, yet ...

We perform Bell's measurement for the non-separable correlation between polarization and orbital angular momentum from the same classical vortex beam. The violation of Bell's inequality for such a non-separable classical correlation has been demonstrated experimentally. Based on the classical vortex beam and non-quantum entanglement between the polarization and the orbital angular momentum, the...

We consider the problem of optimal contracts in continuous time, when the agent’s actions are unobservable by the principal. We apply the stochastic maximum principle to give necessary conditions for optimal contracts, both for the case of the utility from the payoff being separable and not separable from the cost of the agent’s effort. The necessary conditions are shown also to be sufficient f...

This paper discusses non-separable 2-D filter banks with diamondshape support. The frequency spectrum partitioning is shown to have higher theoretical coding gain than that of the conventional separable approach in image coding application. However, based on the frequency response structure of the subband filters, they can not be implemented with good frequency characteristic although the passb...

We propose an interpretation of quantum separability based on a physical principle: local time reversal. It immediately leads to a simple characterization of separable quantum states that reproduces results known to hold for binary composite systems and which thereby is complete for low dimensions. We then describe a constructive algorithm for finding the canonical decomposition of separable an...