Quantum Solitons

Motivation

Our central goal is to understand the QCD vacuum — in particular, the nature of and the role played by magnetic monopoles in that vacuum. Monopoles are believed to be essential to confinement and to the structure of the vacuum. However, classical QCD has no monopole solutions and, at low energies, QCD is strongly coupled. As a result, even the most basic characteristics of QCD monopoles are not understood.

A second driving question is the lifetime of the quantum oscillon, and what that lifetime implies for cosmology. Oscillons are long-lived, localized, oscillating field configurations that exist in many models, such as the φ³ and the φ⁴-double-well scalar models, axion models and even the electroweak model. They are attractor solutions that typically dominate the energy budget after violent events such as first order phase transitions, resonant reheating, soliton collisions and string-network collapse. Their lifetime determines whether they survive long enough to matter. For example, it determines the role played by oscillons in baryogenesis — whether these objects can generate the observed matter–antimatter asymmetry.

Methods

We treat classical and quantum solitons and oscillons both analytically and in full simulations. Because they are strongly nonperturbative, standard perturbative techniques break down. To handle the quantum case we use a new formalism called Linearized Soliton Perturbation Theory, a novel lightweight formalism that greatly simplifies previously impractical problems, in particular in situations with a single soliton or oscillon. Lecture notes from the Kraków school on quantum solitons are available on INSPIRE-HEP: Kraków Lectures on Quantum Solitons →

Results thus far

We have used Linearized Soliton Perturbation Theory to find one and two-loop corrections to kink masses and domain wall tensions. We have also used it to calculate form factors, binding energies of bound excitations, lifetimes of unstable excitations and various kink-meson and domain wall-meson elastic and inelastic scattering amplitudes.

Current research

We are currently computing the quantum oscillon lifetime within Linearized Soliton Perturbation Theory. We are also trying to quantize the Q-ball, to understand what classical superradiance will imply in the full quantum theory. We are also studying how oscillon collisions pass the sphaleron barrier and seed first order phase transitions.

Future directions

Going forward we plan to extend Linearized Soliton Perturbation Theory to a wider class of solitons — including supersymmetric kinks, vortices and monopoles, and to understand the implications for cosmology. We are also trying to understand Q-ball and monopole transport in the matter, focusing on the induced excitations of their internal degrees of freedom, their relaxation and the resulting radiation that will be observed at the MANDATE experiment. Our long-term goal is to understand the monopoles in Seiberg-Witten theory, Yang-Mills and QCD, and their role in the vacuum, and implications for hadron structure and hadronization.

Our team

Researchers, postdocs, and students at Alikhanyan National Science Laboratory and our remote PIs.

Principal Investigators

Group Leader

Danial's Group

Remote Laboratory

Talks, reading courses, schools and workshops

Join us for our seminars and special events. All are welcome.

Open positions

We are always looking for curious and motivated researchers. Join our team.

Applications are reviewed on a rolling basis. For inquiries, please contact us.

Get in touch

We welcome collaborations, inquiries, and visits. Reach out to us.