53 citations
- Instituto Politécnico de LisboaPT6 papers
- Centre de Physique ThéoriqueFR1 paper
- Centre National de la Recherche ScientifiqueFR1 paper
- Fundação para a Ciência e TecnologiaPT1 paper
- Institut des Hautes Études ScientifiquesFR1 paper
- Instituto Superior de GestãoPT1 paper
- Rutgers, The State University of New JerseyUS1 paper
- University of CoimbraPT1 paper
- University of IowaUS1 paper
- University of PaduaIT1 paper
- University of PisaIT1 paper
- University of Rome Tor VergataIT1 paper
10 papers
The degree of the bicanonical map of a surface with
Margarida Mendes Lopes, Rita Pardini
In this note it is shown that, given a smooth minimal complex surface of general type S with p_g(S)=0, K^2_S=3, for which the bicanonical map is a morphism, then the degree of the…
Classification of smooth affine spherical varieties
Friedrich Knop, Bart Van Steirteghem
Let G be a complex reductive group. A normal G-variety X is called spherical if a Borel subgroup of G has a dense orbit in X. Of particular interest are spherical varieties which a…
The conceptualization of time and the constancy of the speed of light
Vasco Guerra, Rodrigo de Abreu
In this work we show that the null result of the Michelson-Morley experiment in vacuum is deeply connected with the notion of time. It can be deduced without any mathematics only f…
Images in Christmas Balls
Eef van Beveren, Frieder Kleefeld, George Rupp
We describe light-reflection properties of spherically curved mirrors, like balls in the Christmas tree. In particular, we study the position of the image which is formed somewhere…
Harvesting in a resource dependent age structured Leslie type population model
Rui Dilao, Tiago Domingos, Elman M. Shahverdiev
We analyse the effect of harvesting in a resource dependent age structured population model, deriving the conditions for the existence of a stable steady state as a function of fer…
Modelling butterfly wing eyespot patterns
Rui Dilao, Joaquim Sainhas
Eyespots are concentric motifs with contrasting colours on butterfly wings. Eyespots have intra- and inter-specific visual signalling functions with adaptive and selective roles. W…