Results 31 to 40 of about 1,320,114 (290)

Rediscovering a little known fact about the t-test and the F-test: Algebraic, Geometric, Distributional and Graphical Considerations

, 2022
We discuss the role that the null hypothesis should play in the construction of a test statistic used to make a decision about that hypothesis.
MacEachern, Steven N., Peruggia, Mario, Sinnott, Jennifer A.   +2 more
core   +1 more source

Exact four dimensional string solutions and Toda-like sigma models from `null-gauged' WZNW theories [PDF]

, 1994
We construct a new class of exact string solutions with a four dimensional target space metric of signature ($-,+,+,+$) by gauging the independent left and right nilpotent subgroups with `null' generators of WZNW models for rank 2 non-compact groups $G$.
A.A. Tseytlin, Alekseev, Amati, Antoniadis, Balog, Balog, Banados, Bardakci, Bardakci, Bars, Bars, Bars, Bars, Bars, Bershadsky, Bilal, Bilal, Buscher, Buscher, C. Klimčík, Callan, Chung, Di Vecchia, Di Vecchia, Dijkgraaf, Fehér, Forgács, Fradkin, Gawedzki, Gawedzki, Gerasimov, Gershon, Gervais, Gervais, Giddings, Ginsparg, Giveon, Güven, Helgason, Horne, Horowitz, Horowitz, Horowitz, Hořava, Humphreys, Jack, Kaloper, Karabali, Karabali, Klimčík, Kounnas, Leznov, Leznov, Mansfield, Mohammedi, Nappi, Nappi, O'Raifeartaigh, O'Raifeartaigh, Olive, Olive, Olive, Petrov, Polyakov, Roček, Roček, Rudd, Schwarz, Sen, Sfetsos, Sfetsos, Tseytlin, Tseytlin, Tseytlin, Tseytlin, Tseytlin, Tseytlin, Tseytlin, Witten, Witten, Witten   +80 more
core   +2 more sources

Inferring monopartite projections of bipartite networks: an entropy-based approach

New Journal of Physics, 2017
Bipartite networks are currently regarded as providing a major insight into the organization of many real-world systems, unveiling the mechanisms driving the interactions occurring between distinct groups of nodes.
Fabio Saracco, Mika J Straka, Riccardo Di Clemente, Andrea Gabrielli, Guido Caldarelli, Tiziano Squartini   +5 more
doaj   +1 more source

Uniqueness of de Sitter space [PDF]

, 2007
All inextendible null geodesics in four dimensional de Sitter space dS^4 are complete and globally achronal. This achronality is related to the fact that all observer horizons in dS^4 are eternal, i.e.
Andersson L, Bengtsson I, Bousso R, Cheeger J, Didier A Solis, Galloway G J, Galloway G J, Gao S, Gregory J Galloway, Hawking S W, Kriele M, Lee J M, Mess G, O'Neill B, Penrose R, Sachs R K, Schimming R, Spivak M, Wald R   +18 more
core   +3 more sources

Null physical states in string models [PDF]

Journal of High Energy Physics, 2013
This note is a brief addendum to my article Nucl. Phys. B 864 (2012) 285, [arXiv: 1110.5510], which discusses the noghost theorem in Ramond sectors of string models. In this addendum we derive additional information about the structure of null physical states in the Ramond-Neveu-Schwarz model.
openaire   +3 more sources

Phylogenetic clustering of fungal communities in human‐disturbed streams

Ecosphere, 2016
Phylogenetic community structure is increasingly used to examine community assembly, but the influence of anthropogenic disturbance on phylogenetic community structure remains little explored.
H. Mykrä, M. Tolkkinen, A. M. Markkola, A.‐M. Pirttilä, T. Muotka   +4 more
doaj   +1 more source

Fluctuating ecological networks: A synthesis of maximum‐entropy approaches for pattern detection and process inference

Methods in Ecology and Evolution, 2022
Ecological networks such as plant–pollinator systems and food webs vary in space and time. This variability includes fluctuations in global properties such as the total number and intensity of interactions in the network but also in the number and ...
Tancredi Caruso, Giulio Virginio Clemente, Matthias C. Rillig, Diego Garlaschelli   +3 more
doaj   +1 more source

Mate Choice and Null Models [PDF]

Philosophy of Science, 2020
Biologists have proposed a variety of explanations for extravagant sexual displays, and controversies over explanations define the history of sexual selection research. Recently, Richard Prum has defended Darwin’s idea that the evolution of sexual displays is driven by arbitrary and nonadaptive preferences of potential mates.
openaire   +1 more source

Null models for multioptimized large-scale network structures [PDF]

Physical Review E, 2020
11 pages, 10 ...
Sebastian Morel-Balbi, Tiago P. Peixoto
openaire   +4 more sources

Repeatable light paths in the shearfree normal cosmological models

, 2011
Conditions for the existence of repeatable light paths (RLPs) in the shearfree normal cosmological models are investigated. It is found that in the conformally nonflat models the only RLPs are radial null geodesics (in the spherical case) and their ...
Krasiński, Andrzej
core   +1 more source