32 citations · 139 across the 11 of their papers we have counts for
10 papers
Non-Abelian Geometric Phases in Triangular Structures And Universal SU(2) Control in Shape Space
J. Dai, A. Molochkov, A. J. Niemi +1
We construct holonomic quantum gates for qubits that are encoded in the near-degenerate vibrational -doublet of a deformable three-body system. Using Kendall's shape theory, we…
Multiple scales and phases in discrete chains with application to folded proteins
Anna Sinelnikova, Antti J. Niemi, Johan Nilsson +1
Chiral heteropolymers such as larger globular proteins can simultaneously support multiple length scales. The interplay between different scales brings about conformational diversi…
Non-Abelian Supercurrents and de Sitter Ground State in Electroweak Theory
M. N. Chernodub, Ludvig Faddeev, Antti J. Niemi
We show that gauge symmetry breaking in the Weinberg-Salam model can be implemented by a mere change of variables and without any explicit gauge fixing. The change of variables ent…
On the infrared limit of the Chern-Simons-Proca theory
A. J. Niemi, V. V. Sreedhar
We investigate a modification of the 2+1 dimensional abelian Chern-Simons theory, obtained by adding a Proca mass term to the gauge field. We are particularly interested in the inf…
Equivariant Morse theory and quantum integrability
A. J. Niemi, K. Palo
We investigate an equivariant generalization of Morse theory for a general class of integrable models. In particular, we derive equivariant versions of the classical Poincaré-Hopf…
On the Duistermaat-Heckman Integration Formula And Integrable Models
T. Karki, A. J. Niemi
In this article we review the Duistermaat-Heckman integration formula and the ensuing equivariant cohomology structure, in the finite dimensional case. In particular, we discuss th…
On Quantum Integrability and the Lefschetz Number
A. J. Niemi, K. Palo
Certain phase space path integrals can be evaluated exactly using equivariant cohomology and localization in the canonical loop space. Here we extend this to a general class of mod…
On Exact Evaluation of Path Integrals
A. J. Niemi, O. Tirkkonen
Some mistakes have been corrected
Cohomological Partition Functions for a Class of Bosonic Theories
Antti J. Niemi, O. Tirkkonen
We argue, that for a general class of nontrivial bosonic theories the path integral can be related to an equivariant generalization of conventional characteristic classes.
Index Theorems and Loop Space Geometry
A. Hietamaki, A. J. Niemi
We investigate the evaluation of the Dirac index using symplectic geometry in the loop space of the corresponding supersymmetric quantum mechanical model. In particular, we find th…