Inverting Onto Functions and Polynomial Hierarchy

In this paper we construct an oracle under which the polynomial hierarchy is infinite but there are non-invertible polynomial time computable multivalued onto functions

Anonymous Graph Exploration with Binoculars

International audienceWe investigate the exploration of networks by a mobile agent. It is long known that, without global information about the graph, it is not possible to make the agent halts after the exploration except if the graph is a tree. We therefore endow the agent with binoculars, a sensing device that can show the local structure of the environment at a constant distance of the agent current location.We show that, with binoculars, it is possible to explore and halt in a large class of non-tree networks. We give a complete characterization of the class of networks that can be explored using binoculars using standard notions of discrete topology. This class is much larger than the class of trees: it contains in particular chordal graphs, plane triangulations and triangulations of the projective plane. Our characterization is constructive, we present an Exploration algorithm that is universal; this algorithm explores any network explorable with binoculars, and never halts in non-explorable networks

Actual changes in system of urban planning in post-socialist city: the case of Prague

After the change of political system in Czechoslovakia (1989) came also a lot of social, economical and cultural changes. Today, all the Czech cities stay in front of the biggest change of city planning philosophy in last two decades. Prague, the capital city of Czech Republic, decided for a big institutional transition in 2012. The municipality, in cooperation with Faculty of Architecture CTU in Prague, is preparing completely pioneering methodology for quality commissioning of land use plans and, in cooperation with the new Institute of Planning and Development, is preparing innovative system of city planning. There are new ordinances, laws, regulations, tourist trade strategies and many other documents. Prague, as one of the strongest regions in East-Central Europe, can be seen like a laboratory of current development of post-socialist city. The new methodology of Metropolitan Plan could be a key to success

Decoding millimetre-wave spectra of 2-iminopropanenitrile, a candidate for astronomical observations

International audienceAims. The recent detection of cyanomethanimine in the interstellar medium makes its methyl derivative, 2-iminopropanenitrile (CH3C(CN)NH), a promising candidate for an interstellar detection. The aim of this work is to extend the current knowledge of the laboratory rotational spectrum to higher frequencies, which is an essential prerequisite for an identification of the molecular species in the interstellar medium by millimetre-wave astronomy. Methods. The room-temperature rotational spectrum of 2-iminopropanenitrile has been measured in several frequency regions between 128 and 329 GHz. The A-E splittings of the rotational transitions arising from the methyl top internal rotation were analysed employing the ERHAM and XIAM programs. Results. A dataset of approximately 900 newly assigned rotational transitions in the ground state of the Z isomer and a set of refined molecular constants, including the internal rotation parameters, are reported. Moreover, this work provides the first spectral characterisation of the less stable E isomer ground state, as well as the three lowest-lying vibrationally excited states of the Z isomer, v(21) = 1, v(14) = 1, and v(20) = 1. This comprehensive spectroscopic study will allow a search for 2-iminopropanenitrile in the millimetre-wave surveys of interstellar sources, such as those recorded by the Atacama Large Millimeter/submillimeter Array

Inverting Onto Functions and Polynomial Hierarchy

In this paper we construct an oracle under which the polynomial hierarchy is infinite but there are non-invertible polynomial time computable multivalued onto functions

Millimetre-wave spectroscopy of 2-hydroxyprop-2-enal and an astronomical search with ALMA

Context. Several sugar-like molecules have been found in the interstellar medium (ISM). The molecule studied in this work, 2-hydroxyprop-2-enal, is among the candidates to be searched for, as it is a dehydration product of C3 sugars and contains structural motifs that are typical for some interstellar molecules. Furthermore, it has recently been predicted that it is more abundant in the ISM than its tentatively detected isomer 3-hydroxypropenal. Aims. So far, only low-frequency microwave data of 2-hydroxyprop-2-enal have been published. The aim of this work is to deepen our knowledge about the millimetre-wave spectrum of 2-hydroxyprop-2-enal, enabling its detailed search towards astronomical objects. In particular, we target the solar-type protostar IRAS 16293-2422 and the star-forming region Sagittarius (Sgr) B2(N). Methods. The rotational spectrum of 2-hydroxyprop-2-enal was measured and analysed in the frequency regions of 128-166 GHz and 285-329 GHz. The interstellar exploration towards IRAS 16293-2422 was based on the Atacama Large Millimeter/submillimeter Array (ALMA) data of the Protostellar Interferometric Line Survey (PILS). We also used the imaging spectral line survey ReMoCA performed with ALMA towards Sgr B2(N) to search for 2-hydroxyprop-2-enal in the ISM. We modelled the astronomical spectra under the assumption of local thermodynamic equilibrium (LTE). Results. We provide laboratory analysis of hundreds of rotational transitions of 2-hydroxyprop-2-enal in the ground state and the lowest lying excited vibrational state. We report its non-detection towards IRAS 16293 B. The 2-hydroxyprop-2-enal/3-hydroxypropenal abundance ratio is estimated to be ≲0.9–1.3, in agreement with the predicted value of ~1.4. We report the non-detection of 2-hydroxyprop-2-enal towards the hot molecular core Sgr B2(N1), and we did not detect the related aldehydes 2-hydroxypropanal and 3-hydroxypropenal either. We find that these three molecules are at least nine, four, and ten times less abundant than acetaldehyde in this source, respectively. Conclusions. Despite the non-detections of 2-hydroxyprop-2-enal, the results of this work represent a significant improvement on previous investigations in the microwave region and meet the requirements for further searches for this molecule in the ISM