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Isolating block and isolating neighborhood methods have previously been implemented to find transit trajectories and orbits around libration points in the autonomous circular restricted three-body problem. For some applications, the direct computation of these types of trajectories in non-autonomous models more closely approximating real-world ephemerides is beneficial. Here, we apply isolating neighborhood methods to non-autonomous systems, including the elliptic restricted three-body problem (ERTBP). Specifically, simplified isolating neighborhood boundaries are computed around libration points in the ERTBP. These boundaries are used in combination with a bisection method to compute the forward asymptotic trajectories of the isolated invariant set and track orbits around a libration point.

The elliptic restricted three body problem has been well studied. However, the previous formulations of the problem have used a rotating coordinate system to keep the positions of the primary and secondary on the x-axis. This requires the rotation rate of the rotating coordinate system to speed up and slow down. The approach here uses a rotating coordinate system with constant rotation rate. This formulation allows one to conveniently compare solutions of the elliptic problem with solutions of the circular restricted three body problem.

Agents buy and sell services. All services are of equal quality. Buyers choose sellers at random. Monetary and fiscal policies are imposed by a central bank and a central government. Credit is supplied by a commercial banking system. Propensities to buy, sell, and lend depend on account balances, interest rates, tax rates and loan default rates. Computer simulations track weekly sales, loans, account balances, commercial bank profits, solvency and compliance with reserve requirements, and government debt. The model of this economy is fully specified by a computer program. The program allows the user to explore the effects of parameter changes. Monetary and fiscal policies are implemented by choices of parameters such as interest rates and reserve requirements, and government tax and spending rates. Credit supply, consumer confidence, and loan default rates strongly affect the behavior of the economy in terms of sales.

We analyze flat S_3-covers, attempting to create structures parallel to those found in the abelian theory. We use an initial local analysis as a guide in finding a global description., Comment: 25 pages

Given an object over the algebraic closure Qbar of Q, there is often no reason for invariants of the corresponding holomorphic object to be preserved by the absolute Galois group Gal(Qbar/Q), and in general this is not true, although it is sometimes surprising to observe in practice. The case of covers of the projective line branched only over the points 0, 1, and infinity, through Belyi's theorem, leads to Grothendieck's dessins d'enfants program for understanding the absolute Galois group through its faithful action on such covers. This note is motivated by Catanese's question about a higher-dimensional analogue: does the absolute Galois group act faithfully on the deformation equivalence classes of smooth surfaces? (These equivalence classes are of course by definition the strongest deformation invariants.) We give a short proof of a weaker result: the absolute Galois group acts faithfully on the irreducible components of the moduli space of smooth surfaces (of general type, canonically polarized). Bauer, Catanese, and Grunewald have recently answered Catanese's original question using a different construction., Comment: 7 pages

Isolating blocks and isolating neighborhoods have previously been used to compute periodic and quasiperiodic orbits around the collinear libration points in the circular restricted three-body problem. Isolating neighborhoods may be used to further explore the boundary between the Lissajous and quasihalo orbits at en- ergies where the halo orbits have bifurcated from the Lyapunov orbits. A method to compute trajectories that are forward and backward asymptotic to the libration point invariant set using very small velocity corrections is developed here. The method is then used to compute representative trajectories within this region and characterize their behavior.

Previous studies have used isolating blocks to explore the isolated invariant set around the L2 Lagrange point in the circular restricted three-body problem by computing trajectories on the asymptotic set and using them to track particular orbits. Once an initial map of the location of the orbits within the isolated invariant set projected into configuration space has been found, it is possible to further explore these orbits more directly by starting from appropriately chosen points within the mapped space. Here, we develop a method that uses these points to explore the periodic and quasiperiodic orbits within the isolated invariant set.