1,720,986 research outputs found
On 4-manifolds with free fundamental group
No full textWe study the homotopy type of closed 4-manifolds (or oriented Poincare spaces) with free fundamental group. This gives a partial solution to problem N. 4.53 of Kirby, Contemporary Math. 35 (1984). Then we extend the Whitehead-Novikov-Wall theorem for this class of manifolds by using surgery techniques
Lezioni di Topologia Algebrica e Differenziale
No full textQuesto volume raccoglie vari argomenti che gli autori sviluppano nelle loro lezioni di Topologia Algebrica e Differenziale per il secondo biennio del Corso di Laurea in Matematica nelle Universita` di Modena e Reggio Emilia e di Milano. Lo scopo principale del testo, destinato in modo naturale agli studenti, e` quello di fornire le basi tecniche e gli strumenti algebrico-differenziali necessari per comprendere ed affrontare i piu` svariati problemi riguardanti la classificazione e lo studio delle proprieta` geometriche delle varieta` topologiche, lineari a tratti o differenziabili
Manifolds of type C(p, q)
No full textWe study the topology of smooth closed 4-manifolds with free fundamental group. An important subclass consists of the manifolds of type C(p,q) introduced by H. Ikeda and M. Yamashita in Kobe Math. J. 4 (1976). We prove some topological properties and homeomorphism results for such a class of closed 4-manifolds
On pseudo-isotopy classes of homeomorphisms of #_p (S^1 x S^n)
No full textWe study self-homotopy equivalences and diffeomorphisms of the (n+1)-dimensional manifold X given by the connected sum of p copies of S^1 x S^n for any n greater or equal 3. Then we completely determine the group of pseudo-isotopy classes of homeomorphisms of X and extend to dimension n well-known theorems due to F. Laudenbach and V. Poenaru (see Bull. Soc. Math. france 100 (1972)) and J.M. Montesinos (Geometric Topology, Proceed. 1977 Georgia Topology Conf., 1979, Academic Press, 219-238)
Surgery on 3-manifolds with S-1-actions
No full textWe study the topological structure of all 3-manifolds obtained by surgery along principal fibers of a closed orientable connectedS^1-manifold. As a consequence, we give alternative proofs of some classical results due to W. Hell and L. Moser. Moreover, we completely specify the Seifert invariants for the considered manifolds. Finally we classify the manifolds obtained by surgery along certain Seifert links and determine geometric presentations of their fundamental groups
On the effective Yang-Mills Lagrangian and its equation of motion
No full textThe path integral quantization of gauge theories leads to an effective Lagrangian denoted by L_eff. Its associated equation of motion is of the form d_A^* F_A + (1/2) J_A = 0, where J_A is the vacuum polarization current arising from propagation of quantum fields around the background field A. In this paper we will give a more detailed description of the current J_A
A splitting theorem for homotopy equivalent 4-manifolds
No full textWe prove a decomposition theorem for closed connected homotopy equivalent smooth four-manifolds, which partially extends a recent result of Curtis, Freedman, Hsiang and Stong, Invent. Math., 123 (1996), to the non-simply connected case. Then we study the question of when a homotopy equivalence between closed smooth 4-manifolds is homotopic to a topological homeomorphism. In particular, we obtain a new proof of the well-known uniqueness of closed aspherical smooth 4-manifolds with good fundamental groups
A splitting theorem for homotopy equivalent smooth 4-manifolds
Full text linkWe prove a decomposition theorem for closed connected homotopy equivalent smooth four-manifolds, which partially extends a recent result of Curtis et al. (1996) to the non-simply connected case. Then we study the question of when a homotopy equivalence between closed smooth 4-manifolds is homotopic to a topological homeomorphism. In particular, we obtain a new proof of the well-known uniqueness of closed aspherical smooth 4-manifolds with good fundamental groups
On the surgery assembly map
No full textBrowder-Livesay filtrations are used to
calculate the surgery assembly map for
special fundamental grou
On cyclic branched coverings of torus knots
No full textWe prove that the n-fold cyclic coverings of the 3-sphere branched over the torus knots K(p,q), p > q > or = 2, admit spines corresponding to cyclic presentations of groups if p is congruent with 1 mod q
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