Flips, dualities and symmetry enhancements

Higher-order languages: dualities and bisimulation enhancements

Ads/cft Dualities Involving Large 2d N=4 Superconformal Symmetry

We study the duality between string theory on AdS3 × S × S and twodimensional conformal theories with large N = 4 superconformal algebra Aγ. We discuss configurations of intersecting branes which give rise to such near-horizon geometries. We compute the Kaluza-Klein spectrum and propose that the boundary superconformal theory can be described by a sigma model on a suitable symmetric product spa...

Thermal and Nonthermal Pion Enhancements with Chiral Symmetry Restoration

The pion production by sigma decay and its relation with chiral symmetry restoration in a hot and dense matter are investigated in the framework of the Nambu-Jona-Lasinio model. The decay rate for the process σ → 2π to the lowest order in a 1/Nc expansion is calculated as a function of temperature T and chemical potential μ. The thermal and nonthermal enhancements of pions generated by the deca...

Resonant Homoclinic Bifurcations with Orbit Flips and Inclination Flips

Homoclinic bifurcation with one orbit flip, two inclination flips and resonance in the tangent directions of homoclinic orbit is considered. By studying the associated successor functions constructed from a local active coordinate system, we prove the existence of double 1-periodic orbit, 1-homoclinic orbit, and also some coexistence conditions of 1-periodic orbit and 1-homoclinic orbit.

Flips and Spanners

In this thesis, we study two different graph problems. The first problem revolves around geometric spanners. Here, we have a set of points in the plane and we want to connect them with straight line segments, such that there is a path between each pair of points and these paths do not require large detours. If we achieve this, the resulting graph is called a spanner. We focus our attention on t...