We construct an explicit semifree model for the fiber join of two fibrations p: E → B and p′: E′→ B from semifree models of p and p′. Using this model, we introduce a lower bound of the sectional category of a fibration p which can be calculated from any Sullivan model of p and which is closer to the sectional category of p than the classical cohomological lower bound given by the nilpotency of the kernel of p∗: H∗(B; ℚ) → H∗(E; ℚ). In the special case of the evaluation fibration XI → X × X we obtain a computable lower bound of Farber’s topological complexity TC(X). We show that the difference between this lower bound and the classical cohomological lower bound can be arbitrarily large.
Fernández Suárez, Lucía  1 ; Ghienne, Pierre  2 ; Kahl, Thomas  1 ; Vandembroucq, Lucile  1
@article{10_2140_agt_2006_6_119,
author = {Fern\'andez Su\'arez, Luc{\'\i}a and Ghienne, Pierre and Kahl, Thomas and Vandembroucq, Lucile},
title = {Joins of {DGA} modules and sectional category},
journal = {Algebraic and Geometric Topology},
pages = {119--144},
year = {2006},
volume = {6},
number = {1},
doi = {10.2140/agt.2006.6.119},
url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2006.6.119/}
}
TY - JOUR AU - Fernández Suárez, Lucía AU - Ghienne, Pierre AU - Kahl, Thomas AU - Vandembroucq, Lucile TI - Joins of DGA modules and sectional category JO - Algebraic and Geometric Topology PY - 2006 SP - 119 EP - 144 VL - 6 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.2140/agt.2006.6.119/ DO - 10.2140/agt.2006.6.119 ID - 10_2140_agt_2006_6_119 ER -
%0 Journal Article %A Fernández Suárez, Lucía %A Ghienne, Pierre %A Kahl, Thomas %A Vandembroucq, Lucile %T Joins of DGA modules and sectional category %J Algebraic and Geometric Topology %D 2006 %P 119-144 %V 6 %N 1 %U http://geodesic.mathdoc.fr/articles/10.2140/agt.2006.6.119/ %R 10.2140/agt.2006.6.119 %F 10_2140_agt_2006_6_119
Fernández Suárez, Lucía; Ghienne, Pierre; Kahl, Thomas; Vandembroucq, Lucile. Joins of DGA modules and sectional category. Algebraic and Geometric Topology, Tome 6 (2006) no. 1, pp. 119-144. doi: 10.2140/agt.2006.6.119
[1] , Algebraic homotopy, Cambridge Studies in Advanced Mathematics 15, Cambridge University Press (1989)
[2] , , , , Lusternik–Schnirelmann category, Mathematical Surveys and Monographs 103, American Mathematical Society (2003)
[3] , Topological complexity of motion planning, Discrete Comput. Geom. 29 (2003) 211
[4] , Instabilities of robot motion, Topology Appl. 140 (2004) 245
[5] , Relative homotopy invariants of the type of the Lusternik-Schnirelmann category, PhD thesis, FU Berlin (2002)
[6] , , Rational LS category and its applications, Trans. Amer. Math. Soc. 273 (1982) 1
[7] , , , L.S. catégorie et suite spectrale de Milnor–Moore (une nuit dans le train), Bull. Soc. Math. France 111 (1983) 89
[8] , , , Differential graded algebras in topology, from: "Handbook of algebraic topology", North-Holland (1995) 829
[9] , , , Rational homotopy theory, Graduate Texts in Mathematics 205, Springer (2001)
[10] , , Simplicial homotopy theory, Progress in Mathematics 174, Birkhäuser Verlag (1999)
[11] , A proof of Ganea's conjecture for rational spaces, Topology 30 (1991) 205
[12] , On category, in the sense of Lusternik–Schnirelmann, Topology 17 (1978) 331
[13] , Lusternik–Schnirelmann category, from: "Handbook of algebraic topology", North-Holland (1995) 1293
[14] , , Gaps in the Milnor–Moore spectral sequence, Bull. Belg. Math. Soc. Simon Stevin 9 (2002) 265
[15] , The genus of a fiber space, Amer. Math. Soc. Transl. 55 (1966) 49
[16] , On the topology of algorithms I, J. Complexity 3 (1987) 81
[17] , The sectional category of spherical fibrations, Proc. Amer. Math. Soc. 128 (2000) 3137
[18] , Sur le transfert de Becker et Gottlieb, Bull. Belg. Math. Soc. Simon Stevin 6 (1999) 605
Cité par Sources :