Calculations at the prime 2

Author(s):  
Zbigniew Fiedorowicz ◽  
Stewart Priddy
Keyword(s):  
2021 ◽  
Vol 141 (5) ◽  
pp. S75
Author(s):  
G. Yosipovitch ◽  
N. Mollanazar ◽  
S. Ständer ◽  
S.G. Kwatra ◽  
J. Luo ◽  
...  

10.37236/589 ◽  
2011 ◽  
Vol 18 (1) ◽  
Author(s):  
Oliver Schnetz

We consider the number $\bar N(q)$ of points in the projective complement of graph hypersurfaces over $\mathbb{F}_q$ and show that the smallest graphs with non-polynomial $\bar N(q)$ have 14 edges. We give six examples which fall into two classes. One class has an exceptional prime 2 whereas in the other class $\bar N(q)$ depends on the number of cube roots of unity in $\mathbb{F}_q$. At graphs with 16 edges we find examples where $\bar N(q)$ is given by a polynomial in $q$ plus $q^2$ times the number of points in the projective complement of a singular K3 in $\mathbb{P}^3$. In the second part of the paper we show that applying momentum space Feynman-rules over $\mathbb{F}_q$ lets the perturbation series terminate for renormalizable and non-renormalizable bosonic quantum field theories.


2008 ◽  
Vol 64 (2) ◽  
pp. 249-259 ◽  
Author(s):  
Jan B. van Mechelen ◽  
Rene Peschar ◽  
Henk Schenk

The β_1^{\prime}-2 crystal structures of a series of mixed-chain saturated and trans-mono-unsaturated triacylglycerols containing palmitoyl, stearoyl and elaidoyl acyl chains have been solved from high-resolution powder diffraction data, from synchrotron as well as laboratory X-ray sources. The structures crystallized in the space group I2 with two independent molecules forming a dimer in the asymmetric unit, and packed in double-chain length layers. Unlike the corresponding β-2 structures the solved β_1^{\prime}-2 structures have different molecular conformations for the symmetric and the asymmetric mixed triacylglycerols, both with the sn-2 chain in a leg position of the chair-shaped conformation. A transformation to the β-2 structure with the sn-2 chain in the back position is complicated and unlikely to take place in the solid state. A novel β′-2 polymorph of PSS has been crystallized and its structure has been solved. The melting point (239 K) of this so-called β_0^{\prime}-2 polymorph is 2 K above that of the β_1^{\prime}-2 polymorph and almost equal to that of the β-2 polymorph of PSS. The difference in packing of the β_0^{\prime}-2 versus β_1^{\prime}-2 structure explains the slow β_1^{\prime}-2 to β_0^{\prime}-2 phase transition. The transition is strikingly similar to the β2-3 to β1-3 transition in cis-mono-unsaturated triacylglycerols.


Author(s):  
M. C. Crabb ◽  
J. R. Hubbuck ◽  
J. A. W. McCall

SynopsisThe special unitary group SU(n) has the stable homotopy type of a wedge of n − 1 finite complexes. The ‘first’ of these complexes is ΣℂPn–1, which is well known to be indecomposable at the prime 2 whether n is finite or infinite. We show that the ‘second’ finite complex is again indecomposable at the prime 2 when n is finite, but splits into a wedge of two pieces when n is infinite.


Author(s):  
Douglas C. Ravenel

In this paper we will show that certain elements of order p (p an odd prime) on the 2-line of the Adams-Novikov spectral sequence support non-trivial differentials and therefore do not detect elements in the stable homotopy groups of spheres. These elements are analogous to the so-called Arf invariant elements of order 2, hence the title. However, it is evident that the methods presented here do not extend to the prime 2.


1951 ◽  
Vol 71 (12) ◽  
pp. 1341-1343 ◽  
Author(s):  
Shigehiko Sugasawa ◽  
San-ya Akahoshi ◽  
Michihiro Yamada
Keyword(s):  

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