Search results for "Complete"

A note on the closed graph theorem

1977

Completeness number of families of subsets of convergence spaces

2016

International audience; Compactoid and compact families generalize both convergent filters and compact sets. This concept turned out to be useful in various quests, like Scott topologies, triquotient maps and extensions of the Choquet active boundary theorem.The completeness number of a family in a convergence space is the least cardinality of collections of covers for which the family becomes complete. 0-completeness amounts to compactness, finite completeness to relative local compactness and countable completeness to Čech completeness. Countably conditional countable completeness amounts to pseudocompleteness of Oxtoby. Conversely, each completeness class of families can be represented a…

A new Cartan-type property and strict quasicoverings when p = 1 in metric spaces

2018

In a complete metric space that is equipped with a doubling measure and supports a Poincar\'e inequality, we prove a new Cartan-type property for the fine topology in the case $p=1$. Then we use this property to prove the existence of $1$-finely open \emph{strict subsets} and \emph{strict quasicoverings} of $1$-finely open sets. As an application, we study fine Newton-Sobolev spaces in the case $p=1$, that is, Newton-Sobolev spaces defined on $1$-finely open sets.

Q fever: a new ocular manifestation

2011

P Udaondo1,3, S Garcia-Delpech1,2, D Salom1,2, M Garcia-Pous1, M Diaz-Llopis1,21Department of Ophthalmology, Nuevo Hospital Universitario y Politecnico La Fe, Valencia, Spain; 2Faculty of Medicine, Universitat de València, Valencia, Spain; 3Universidad Cardenal Herrera CEU, Valencia, SpainAbstract: Q Fever is a zoonosis caused by Coxiella burnetii. Ocular manifestations are rare in this infection. We describe the case of a man complaining of an intense retro-orbital headache, fever, arthralgia, and bilateral loss of vision, who showed an anterior uveitis accompanied by exudative bilateral inferior retinal detachment and optic disk edema. At the beginning, a Vogt–Koyanag…

Pricing the Option to Surrender in Incomplete Markets

2010

New international accounting standards require insurers to reflect the value of embedded options and guarantees in their products. Pricing techniques based on the Black and Scholes paradigm are often used; however, the hypotheses underneath this model are rarely met. We propose a framework that encompasses the most known sources of incompleteness. We show that the surrender option, joined with a wide range of claims embedded in insurance contracts, can be priced through our tool, and deliver hedging portfolios to mitigate the risk arising from their positions. We provide extensive empirical analysis to highlight the effect of incompleteness on the fair value of the option.

Pricing of forwards and other derivatives in cointegrated commodity markets

2015

Abstract We analyze cointegration in commodity markets, and propose a parametric class of pricing measures which preserves cointegration for forward prices with fixed time to maturity. We present explicit expressions for the term structure of volatility and correlation in the context of our spot price models based on continuous-time autoregressive moving average dynamics for the stationary components. The term structures have many interesting shapes, and we provide some empirical evidence from refined oil future prices at NYMEX defending our modeling idea. Motivated from these results, we present a cointegrated forward price dynamics using the Heath–Jarrow–Morton approach. In this setting, …

Liquidity and dirty hedging in the Nordic electricity market

2012

Abstract Hedging involves tradeoffs in incomplete markets because the number of hedging instruments is limited. Even when an extensive set of hedging instruments is available, the ease with which these instruments can be traded may be highly variable. This study finds systematic variations in liquidity in different segments of the Nordic electricity swap market and analyzes the potential for replacing low-liquidity, delivery-period-matched hedging instruments with more liquid, delivery-period-mismatched hedging instruments. When the costs of implementing such dirty hedging strategies are lower than those of the replaced hedging instruments and the loss of hedge effectiveness is small, dirty…

Coordinated Punishment and the Evolution of Cooperation

2015

In this paper, we analyze a team trust game with coordinated Q1 punishment of the allocator by investors and where there is also a final stage of peer punishment. We study the effect of punishment on the reward and the investment decisions, when the effectiveness and cost of coordinated punishment depend on the number of investors adhering to this activity. The interaction takes place in an overlapping-generations model with heterogeneous preferences and incomplete information. The only long-run outcomes of the dynamics are either a fully cooperative culture (FCC) with high levels of trust and cooperation and fair returns or a non-cooperative culture with no cooperation at all. The basin of…

Are discriminatory procurement policies motivated by protectionism ?

1995

When purchasing goods and services, governments often discriminate in favour of domestic suppliers. It is widely assumed that such behaviour is motivated by protectionism. Although this interpretation is sometimes valid, it is also puzzling. After reviewing some of the puzzles, the paper proposes an alternative explanation of preferential procurement based on the assumption that governmental buyers want to purchase goods and services at minimum cost, but must do this in a context in which, because of the presence of unverifiable services, contracts are necessarily incomplete. The paper argues that preferential purchasing can guarantee the efficient delivery of these unverifiable services.

Unawareness and bankruptcy: A general equilibrium model

1998

International audience; We present a consistent pure-exchange general equilibrium model where agents may not be able to foresee all possible future contingencies. In this context, even with nominal assets and complete asset markets, an equilibrium may not exist without appropriate assumptions. Specific examples are provided. An existence result is proved under the main assumption that there are sufficiently many states that all the agents foresee. An intrinsic feature of the model is bankruptcy, which agents may involuntarily experience in the unforeseen states.