A generalized small model property for languages which force the infinity

This paper deals with formulas of set theory which force the infinity. For such formulas, we provide a technique to infer satisfiability from a finite assignment.Comment: 21 pages. to appear on "Le Matematiche

Supply Chain Control: A Theory of Vertical Integration

Improving a company's bargaining position is often cited as a chief motivation to vertically integrate with suppliers. This paper expands on that view in building a new theory of vertical integration. In my model firms integrate to gain bargaining power against other suppliers in the production process. The cost of integration is a loss of flexibility in choosing the most suitable suppliers for a particular final product. I show that the firms who make the most specific investments in the production process have the greatest incentive to integrate. The theory provides novel insights to the understanding of numerous stylized facts such as the effect of financial development on the vertical structure of firms, the observed pattern from FDI to outsourcing in international trade, the effect of technological obsolescence on organizations, etc.vertical integration, supply chain, bargaining, outside options

Supply Chain Control: A Theory of Vertical Integration

Improving a company's bargaining position is often cited as a chief motivation to vertically integrate with suppliers. This paper expands on that view in building a new theory of vertical integration. In my model firms integrate to gain bargaining power against other suppliers in the production process. The cost of integration is a loss of flexibility in choosing the most suitable suppliers for a particular final product. I show that the firms who make the most specific investments in the production process have the greatest incentive to integrate. The theory provides novel insights to the understanding of numerous stylized facts such as the effect of financial development on the vertical structure of firms, the observed pattern from FDI to outsourcing in international trade, the effect of technological obsolescence on organizations, etc.vertical integration, supply chain, bargaining, outside options

Formative processes with applications to the decision problem in set theory: II. powerset and singleton operators, finiteness predicate

In this paper we solve the satisfiability problem of an extended fragment of set computable theory which "forces the infinity" by a fruitful use of the witness small model property and the theory of formative processes.Comment: this paper has been withdrawn since it has been completely revise

Studying the Interstellar Medium and the inner region of NPS/Loop 1 with shadow observations toward MBM36

We analyzed data from a shadow observation of the high density molecular cloud MBM36 (l~4{\deg}, b~35{\deg}) with Suzaku. MBM36 is located in a region that emits relatively weakly in the 3/4~keV band, compared to the surrounding NPS/Loop 1 structure and the Galactic Bulge. The contrast between a high and low density targets in the MBM36 area allows one to separate the local and distant contributors to the Soft Diffuse X-ray Background, providing a much better characterization of the individual components compared to single pointing observations. We identify two non-local thermal components, one at kT~0.12 keV and one at kT~0.29keV. The colder component matches well with models of emission from the higher latitude region of the Galactic Bulge. The emission of the warmer component is in agreement with models predicting that the NPS is due to a hypershell from the center of the Milky Way. Geometrical and pressure calculations rule out a nearby bubble as responsible for the emission associate with the NPS. Any Galactic Halo/CircumGalactic Halo emission, if present, is outshined by the other components. We also report an excess emission around 0.9~keV, likely due to an overabundance of NeIX.Comment: 8 pages, 3 figures, approved for publication on Ap

X-ray and Sunyaev-Zeldovich properties of the WHIM

We use numerical simulations to predict the soft X-ray ([0.4-0.6] keV) and Sunyaev-Zeldovich signal (at 150 GHz) from the large scale structure in the Universe and then compute 2-point statistics to study the spatial distribution and time evolution of the signals. The average X-ray signal predicted for the WHIM is in good agreement with observational constraints that set it at about 10% of the total Diffuse X-ray Background. The characteristic angle computed with the Autocorrelation Function is of the order of some arcminutes and becomes smaller at higher redshift. The power spectrum peak of the SZ due to the WHIM is at l~10000 and has amplitude of ~0.2 muK^2, about one order of magnitude below the signal measured with telescopes like Planck, ACT, and SPT. Even if the high-redshift WHIM signal is too weak to be detected using X-rays only, the small-scale correlation between X-ray and SZ maps is dominated by the high-redshift WHIM. This makes the analysis of the SZ signal in support of X-rays a promising tool to study the early time WHIM.Comment: 13 Pages, 10 Figures, Accepted for Publication on Ap