Search for dissertations about: "conjecture"

Showing result 21 - 25 of 120 swedish dissertations containing the word conjecture.

  2. 21. Identity of proofs

    Author : Filip Widebäck; Peter Schroeder-Heister; Stockholms universitet; []
    Keywords : Theoretical Philosophy; teoretisk filosofi;

    Abstract : In the early seventies it was conjectured that a certain mathematically well-defined equivalence relation (bh-equivalence) on proofs in natural deduction captures the informal notion of identity of proofs. The conjecture can be divided into two parts, a soundness part and a completeness part. READ MORE

  4. 22. Graded lie algebras in local algebra and rational homotopy

    Author : Rikard Bøgvad; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : This thesis consists of three papers, [A – C]The old conjecture that Poincaré-series of local noetherian rings are rational was disproved by Anick in 1979. Building upon his counter-example, as analyzed by Löfwall-Roos, I construct a Gorenstein ring with transcendental Poincaré-series; by a method of Roos this also gives a manifold whose loopspace has transcendental Poinaré-Betti series. READ MORE

  5. 23. Small energy isotopies of loose Legendrian submanifolds

    Author : Lukas Nakamura; Tobias Ekholm; Álvaro del Pino Gómez; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; contact geometry; Legendrian submanifolds; Chekanov-Shelukhin-Hofer energy; Mathematics; Matematik;

    Abstract : In the first paper, we prove that for a closed Legendrian submanifold L of dimension n>2 with a loose chart of size η, any Legendrian isotopy starting at L can be C0-approximated by a Legendrian isotopy with energy arbitrarily close to η/2. This in particular implies that the displacement energy of loose displaceable Legendrians is bounded by half the size of its smallest loose chart, which proves a conjecture of Dimitroglou Rizell and Sullivan. READ MORE

  6. 24. Topics in Hardness of Approximation and Social Choice Theory

    Author : Marcus Isaksson; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Hardness of approximation; social choice theory; Gibbard-Satterthwaite; max-q-cut; Condorcet voting; linear threshold functions.; Hardness of approximation;

    Abstract : Tools from Fourier analysis of Boolean functions have commonly been used to prove results both in hardness of approximation in computer science and in the study of voting schemes in social choice theory. In this thesis we consider various topics in both these contexts. READ MORE

  7. 25. Enumerative combinatorics related to partition shapes

    Author : Jonas Sjöstrand; Anders Björner; Christian Krattenthaler; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; partition shape; sign-imbalance; Robinson-Schensted correspondence; chess tableau; restricted word; cylindrical lattice walk; Poincaré polynomial; Bruhat interval; rook polynomial; pattern avoidance; partitionsform; teckenobalans; Robinson-Schensted-korrespondens; schacktablå; begränsade ord; cylindriska latticestigar; poincarépolynom; bruhatintervall; tornpolynom; mönsterundvikande permutation; MATHEMATICS; MATEMATIK;

    Abstract : This thesis deals with enumerative combinatorics applied to three different objects related to partition shapes, namely tableaux, restricted words, and Bruhat intervals. The main scientific contributions are the following. READ MORE