Publications (109)
Sensitivity to the initial conditions of the Time-Dependent Density Functional Theory
Aurel Bulgac, Ibrahim Abdurrahman, Gabriel WlazÅowski
Time-Dependent Density Functional Theory is mathematically formulated through non-linear coupled time-dependent 3-dimensional partial differential equations and it is natural to ex…
A critical assessment of the current implementations of the Generator Coordinate Method
Aurel Bulgac
The generator coordinate method (GCM) was introduced in nuclear physics by Wheeler and independently by Peierls and their collaborators in 1950's and it is still one of the mostly…
Coordinate-Space Solver for Superfluid Many-Fermion Systems with Shifted Conjugate Orthogonal Conjugate Gradient Method
Shi Jin, Aurel Bulgac, Kenneth Roche +1
Self-consistent approaches to superfluid many-fermion systems in 3-dimensions (and subsequent time-dependent approaches) require a large number of diagonalizations of very large di…
Dynamics of a Simple Quantum System in a Complex Environment
Aurel Bulgac, Gui DoDang, Dimitri Kusnezov
We present a theory for the dynamical evolution of a quantum system coupled to a complex many-body intrinsic system/environment. By modelling the intrinsic many-body system with pa…
Nuclear hydrodynamics in the inner crust of neutron stars
Piotr Magierski, Aurel Bulgac
In the inner crust of a neutron star, due to the high density and pressure, nuclei which are still present, are immersed in a neutron superfluid. One then expects that the dynamica…
Eigenstates for billiards of arbitrary shapes
Aurel Bulgac, Piotr Magierski
A new algorithm for determining the eigenstates of n-dimensional billiards is presented. It is based on the application of the Cauchy theorem for the determination of the null spac…
Exotic Stochastic Processes from Complex Quantum Environments
Dimitri Kusnezov, Aurel Bulgac, Giu Do Dang
Stochastic processes are shown to emerge from the time evolution of complex quantum systems. Using parametric, banded random matrix ensembles to describe a quantum chaotic environm…
The Vortex State in a Strongly Coupled Dilute Atomic Fermionic Superfluid
Aurel Bulgac, Yongle Yu
We show that in a dilute Fermionic superfluid, when the Fermions interact with an infinite scattering length, a vortex state is characterized by a strong density depletion along th…
Time-Dependent Density Functional Theory and the Real-Time Dynamics of Fermi Superfluids
Aurel Bulgac
I describe the Time-Dependent Superfluid Local Density Approximation, which is an adiabatic extension of the Density Functional Theory to superfluid Fermi systems and their real-ti…
Quantum corrections to the ground state energy of inhomogeneous neutron matter
Aurel Bulgac, Piotr Magierski
We estimate the quantum corrections to the ground state energy in neutron matter (which could be termed as well either shell correction energy or Casimir energy) at subnuclear dens…
Quantum Shock Waves and Domain Walls in the Real-Time Dynamics of a Superfluid Unitary Fermi Gas
Aurel Bulgac, Yuan-Lung, Luo +1
We show that in the collision of two superfluid fermionic atomic clouds one observes the formation of quantum shock waves as discontinuities in the number density and collective fl…
Quantum Lévy Processes and Fractional Kinetics
Dimitri Kusnezov, Aurel Bulgac, Giu Do Dang
Exotic stochastic processes are shown to emerge in the quantum evolution of complex systems. Using influence function techniques, we consider the dynamics of a system coupled to a…
Time-Dependent Superfluid Local Density Approximation
Aurel Bulgac, Michael McNeil Forbes
The time-dependent superfluid local density approximation (TDSLDA) is an extension of the Hohenberg-Kohn density functional theory (DFT) to time-dependent phenomena in superfluid f…
Microscopic Calculations of Vortex-Nucleus Interaction in the Neutron Star Crust
Kazuyuki Sekizawa, Gabriel WlazÅowski, Piotr Magierski +2
We investigate the dynamics of a quantized vortex and a nuclear impurity immersed in a neutron superfluid within a fully microscopic time-dependent three-dimensional approach. The…
Induced Fission of Pu within a Real-Time Microscopic Framework
Aurel Bulgac, Piotr Magierski, Kenneth J. Roche +1
We describe the fissioning dynamics of Pu240 from a configuration in the proximity of the outer fission barrier to full scission and the formation of the fragments within an implem…
Fermionic Casimir Effect in Case of Andreev Reflection
Aurel Bulgac, Piotr Magierski, Andreas Wirzba
We describe the Fermionic Casimir effect in the case of two spherical superfluid scatterers immersed in a normal Fermi system. It is shown that due to the focusing property of Andr…
A Minimal Nuclear Energy Density Functional
Aurel Bulgac, Michael McNeil Forbes, Shi Jin +2
We present a minimal nuclear energy density functional (NEDF) called "SeaLL1" that has the smallest number of possible phenomenological parameters to date. SeaLL1 is defined by 7 s…
Neutron stars and the fermionic Casimir effect
Piotr Magierski, Aurel Bulgac, Paul-Henri Heenen
The inner crust of neutron stars consists of nuclei of various shapes immersed in a neutron gas and stabilized by the Coulomb interaction in the form of a crystal lattice. The scat…
Onset of a Pseudogap Regime in Ultracold Fermi Gases
Piotr Magierski, Gabriel WlazÅowski, Aurel Bulgac
We show, using an ab initio approach based on Quantum Monte Carlo technique, that the pseudogap regime emerges in ultracold Fermi gases close to the unitary point. We locate the on…
A generalized local approximation to the exchange potential
Aurel Bulgac, Caio Lewenkopf, Vadim Mickrjukov
A new method to obtain a local parameterization for the exchange term in the many--body electronic problem is presented. The approach amounts to the introduction of a coordinate de…
The spatial profile of the matter distribution in a dilute atomic-molecular Fermi cloud
Aurel Bulgac
A dilute atomic-molecular fermion in a trap acquires a rather complex layered spatial structure. At very low temperatures, typically at the center of the trap, a superfluid bosonic…
Use of the Discrete Variable Representation Basis in Nuclear Physics
Aurel Bulgac, Michael McNeil Forbes
The discrete variable representation (DVR) basis is nearly optimal for numerically representing wave functions in nuclear physics: Suitable problems enjoy exponential convergence,…
Proton Single Particle Energy Shifts due to Coulomb Correlations
Aurel Bulgac, Vasily R. Shaginyan
A theoretically consistent approach to the calculation of the Coulomb correlation corrections to the single--particle energies is presented. New contributions to the single--partic…
Comment on "Structure of a Quantized Vortex near the BCS-BEC Crossover in an Atomic Fermi Gas"
Aurel Bulgac
A comment on the letter by M. Machida and T. Koyama, Phys. Rev. Lett. {\bf 94}, 140401 (2005) and also on the preprint by Y. Kawaguchi and T. Ohmi, cond-mat/0411018.
Superfluid Local Density Approximation: A Density Functional Theory Approach to the Nuclear Pairing Problem
Aurel Bulgac
I describe the foundation of a Density Functional Theory approach to include pairing correlations, which was applied to a variety of systems ranging from dilute fermions, to neutro…
Non-Markovian character and irreversibility of real-time quantum many-body dynamics
Aurel Bulgac, Matthew Kafker, Ibrahim Abdurrahman +1
The presence of pairing correlations within the time-dependent density functional theory (TDDFT) extension to superfluid systems, is tantamount to the presence of a quantum collisi…
Strength of the Vortex-Pinning Interaction from Real-Time Dynamics
Aurel Bulgac, Michael McNeil Forbes, Rishi Sharma
We present an efficient and general method to compute vortex-pinning interactions - which arise in neutron stars, superconductors, and trapped cold atoms - at arbitrary separations…
Cooper pairing above the critical temperature in a unitary Fermi gas
Gabriel WlazÅowski, Piotr Magierski, JoaquÃn E. Drut +2
We present an ab initio determination of spin responses of the unitary Fermi gas, based on finite temperature quantum Monte Carlo calculations and the Kubo linear-response formalis…
The temperature evolution of the shear viscosity in a unitary Fermi gas
Gabriel WlazÅowski, Piotr Magierski, Aurel Bulgac +1
We present an ab initio determination of the shear viscosity for the unitary Fermi gas based on finite temperature quantum Monte Carlo (QMC) calculations and the Kubo linear-respon…
Time-Dependent Density Functional Theory Description of U(n,f), Pu(n,f) and Np(n,f) Reactions
Aurel Bulgac, Ibrahim Abdurrahman, Matthew Kafker +1
In nuclei with an odd nucleon number the non-vanishing spin number density is the source of a pseudo-magnetic field, which favors the splitting of the nucleon Cooper pairs. Such an…
Measures of complexity and entanglement in fermionic many-body systems
Aurel Bulgac, Matthew Kafker, Ibrahim Abdurrahman
There is no unique and widely accepted definition of the complexity measure (CM) of a many-fermion wave function in the presence of interactions. The simplest many-fermion wave fun…
Quantized Superfluid Vortex Rings in the Unitary Fermi Gas
Aurel Bulgac, Michael McNeil Forbes, Michelle M. Kelley +2
In a recent article, Yefsah et al. [Nature 499, 426 (2013)] report the observation of an unusual excitation in an elongated harmonically trapped unitary Fermi gas. After phase impr…
Vortex pinning and dynamics in the neutron star crust
Gabriel WlazÅowski, Kazuyuki Sekizawa, Piotr Magierski +2
The nature of the interaction between superfluid vortices and the neutron star crust, conjectured by Anderson and Itoh in 1975 to be at the heart vortex creep and the cause of glit…
Dynamics of Fragmented Condensates and Macroscopic Entanglement
Aurel Bulgac, Shi Jin
The relative phase of the order parameters in the collision of two condensates can influence the outcome of their collision in the case of weak coupling. With increasing interactio…
Turbulent-like Diffusion in Complex Quantum Systems
Dimitri Kusnezov, Aurel Bulgac, Gui Do Dang
We study a quantum particle propagating through a ``quantum mechanically chaotic'' background, described by parametric random matrices with only short range spatial correlations. T…
The Asymmetric Superfluid Local Density Approximation (ASLDA)
Aurel Bulgac, Michael McNeil Forbes
Here we describe the form of the Asymmetric Superfluid Local Density Approximation (ASLDA), a Density Functional Theory (DFT) used to model the two-component unitary Fermi gas. We…
Framework for Polarized Superfluid Fermion Systems
Aurel Bulgac
I discuss the advantages and disadvantages of several procedures, some known and some new, for constructing stationary states within the mean field approximation for a system with…
Local Density Approximation for Pairing Correlations in Nuclei
Aurel Bulgac, Yongle Yu
We introduce a natural and simple to implement renormalization scheme of the Hartree-Fock-Bogoliubov (HFB) equations for the case of zero range pairing interaction. This renormaliz…
Generation and Dynamics of Quantized Vortices in a Unitary Fermi Superfluid
Aurel Bulgac, Yuan-Lung, Luo +3
Superfluidity and superconductivity are remarkable manifestations of quantum coherence at a macroscopic scale. The dynamics of superfluids has dominated the study of these systems…
Life Cycle of Superfluid Vortices and Quantum Turbulence in the Unitary Fermi Gas
Gabriel WlazÅowski, Aurel Bulgac, Michael McNeil Forbes +1
The unitary Fermi gas (UFG) offers an unique opportunity to study quantum turbulence both experimentally and theoretically in a strongly interacting fermionic superfluid. It yields…
New developments in fission studies within the time-dependent density functional theory framework
Aurel Bulgac
We have extended significantly the microscopic description of the fission process by examining a larger set of observables. We extract neutron and proton numbers of fission fragmen…
The Long Journey from Ab Initio Calculations to Density Functional Theory for Nuclear Large Amplitude Collective Motion
Aurel Bulgac
At present there are two vastly different ab initio approaches to the description of the the many-body dynamics: the Density Functional Theory (DFT) and the functional integral (pa…
Fermionic and Bosonic Bubbles and Foam
Aurel Bulgac, Siu A. Chin, Harald A. Forbert +2
The positioning of one or more bubbles inside a many fermion or boson system, does not affect the volume, surface or curvature terms in the liquid drop expansion of the total energ…
Energy Density Functional Approach to Superfluid Nuclei
Yongle Yu, Aurel Bulgac
We show that within the framework of a simple local nuclear energy density functional (EDF), one can describe accurately the one-- and two--nucleon separation energies of semi--mag…
Temperature Dependence of the Optical Response of Small Sodium Clusters
Aurel Bulgac, Caio Lewenkopf
We present an analysis of the temperature dependence of the optical response of small sodium clusters in a temperature range bracketing the melting phase transition. When the tempe…
On the specific heat of a fermionic atomic cloud in the unitary regime
Aurel Bulgac
In the unitary regime, when the scattering amplitude greatly exceeds in magnitude the average inter-particle separation, and below the critical temperature thermal properties of an…
Unitary evolution with fluctuations and dissipation
Aurel Bulgac, Shi Jin, Ionel Stetcu
We outline an extension of the classical Langevin equation to a quantum formulation of the treatment of dissipation and fluctuations of all collective degrees of freedom with unita…
Nuclear Energy Density Functionals: What do we really know?
Aurel Bulgac, Michael McNeil Forbes, Shi Jin
We present the simplest nuclear energy density functional (NEDF) to date, determined by only 4 significant phenomenological parameters, yet capable of fitting measured nuclear mass…
A Unitary Fermi Supersolid: The Larkin-Ovchinnikov Phase
Aurel Bulgac, Michael McNeil Forbes
We present strong theoretical evidence that a Larkin-Ovchinnikov (LOFF/FFLO) pairing phase is favoured over the homogeneous superfluid and normal phases in three-dimensional unitar…
Quantum Friction: Cooling Quantum Systems with Unitary Time Evolution
Aurel Bulgac, Michael McNeil Forbes, Kenneth J. Roche +1
We introduce a type of quantum dissipation -- local quantum friction -- by adding to the Hamiltonian a local potential that breaks time-reversal invariance so as to cool the system…
Casimir interaction between normal or superfluid grains in the Fermi sea
Andreas Wirzba, Aurel Bulgac, Piotr Magierski
We report on a new force that acts on cavities (literally empty regions of space) when they are immersed in a background of non-interacting fermionic matter fields. The interaction…
The LISE package: solvers for static and time-dependent superfluid local density approximation equations in three dimensions
Shi Jin, Kenneth J. Roche, Ionel Stetcu +2
Nuclear implementation of the density functional theory (DFT) is at present the only microscopic framework applicable to the whole nuclear landscape. The extension of DFT to superf…
Nuclear Fission Dynamics: Past, Present, Needs, and Future
Aurel Bulgac, Shi Jin, Ionel Stetcu
Recent developments in theoretical modeling and in computational power have allowed us to make significant progress on a goal not achieved yet in nuclear theory: a fully microscopi…
Broyden's Method in Nuclear Structure Calculations
Andrzej Baran, Aurel Bulgac, Michael McNeil Forbes +4
Broyden's method, widely used in quantum chemistry electronic-structure calculations for the numerical solution of nonlinear equations in many variables, is applied in the context…
Multi-Nucleon Transfer Reactions and the Creation and the Evolution of the Compound Nucleus
Matthew Kafker, Aurel Bulgac
There is no microscopic quantum approach based on the many-body time-dependent Schrödinger equation which capable to describe the formation and the evolution of a compound nucleus…
Quantum Corrections to Dilute Bose Liquids
Paulo F. Bedaque, Aurel Bulgac, Gautam Rupak
It was recently shown (A. Bulgac. Phys. Rev. Lett. {\bf 89}, 050402 (2002)) that an entirely new class of quantum liquids with widely tunable properties could be manufactured from…
Shell Effects in Bubble Nuclei, Atomic Clusters, and Inhomogeneous Neutron Matter
Aurel Bulgac, Piotr Magierski
We analyze the character of the shell effects/Casimir energy in inhomogeneous fermion systems. We estimate magnitude of the shell effects and discuss their dependence on a number o…
Quantum Dissipation
Aurel Bulgac, Giu Do Dang, Dimitri Kusnezov
We address the question of the microscopic origin of dissipation in collective motion of a quantum many--body system in the framework of a parametric random matrix approach to the…
Spatial orientation of the fission fragment intrinsic spins and their correlations
Guillaume Scamps, Ibrahim Abdurrahman, Matthew Kafker +2
New experimental and theoretical results obtained in 2021 made it acutely clear that more than 80 years after the discovery of nuclear fission we do not understand the generation a…
Quantum Monte Carlo Simulations of the BCS-BEC Crossover at Finite Temperature
Aurel Bulgac, Joaquin E. Drut, Piotr Magierski
The Quantum Monte Carlo method for spin 1/2 fermions at finite temperature is formulated for dilute systems with an s-wave interaction. The motivation and the formalism are discuss…
Bubble Nuclei, Neutron Stars and Quantum Billiards
Aurel Bulgac, Piotr Magierski
We briefly review the significance of quantum corrections in the total energy of systems with voids: bubble nuclei, atomic clusters and the inhomogeneous phase of neutron stars.
Large Amplitude Dynamics of the Pairing Correlations in a Unitary Fermi Gas
Aurel Bulgac, Sukjin Yoon
A unitary Fermi gas has a surprisingly rich spectrum of large amplitude modes of the pairing field alone, which defies a description within a formalism involving only a reduced set…
Microscopic Theory of Nuclear Fission
Aurel Bulgac, Shi Jin, Piotr Magierski +2
We describe the fission dynamics of Pu within an implementation of the Density Functional Theory (DFT) extended to superfluid systems and real-time dynamics. We demonstrate…
W-SLDA Toolkit: A simulation platform for ultracold Fermi gases
Gabriel WlazÅowski, Piotr Magierski, Michael McNeil Forbes +1
We present the W-SLDA Toolkit, a general-purpose software package for simulating ultracold Fermi gases within the framework of density functional theory and its time-dependent exte…
Computational Nuclear Quantum Many-Body Problem: The UNEDF Project
Scott Bogner, Aurel Bulgac, Joseph A. Carlson +28
The UNEDF project was a large-scale collaborative effort that applied high-performance computing to the nuclear quantum many-body problem. UNEDF demonstrated that close association…
Entanglement entropy, single-particle occupation probabilities, and short-range correlations
Aurel Bulgac
For quantum many-body systems with short-range correlations (SRCs), the intimate relationship between their magnitude, the behavior of the single-particle occupation probabilities…
Signatures of Superfluidity in Dilute Fermi Gases near a Feshbach Resonance
Aurel Bulgac, Yongle Yu
We present a brief account of the most salient properties of vortices in dilute atomic Fermi superfluids near a Feshbach resonance.
Atomic-Molecular Condensates with Large Positive Scattering Length
Aurel Bulgac, Paulo F. Bedaque
We show that in the limit of large and positive atom--atom scattering length the properties of an atomic--molecular Bose--Einstein Condensate (amBEC) are determined by an universal…
Spatial structure of a vortex in low density neutron matter
Yongle Yu, Aurel Bulgac
We study in a fully selfconsistent approach the structure of a vortex in low density superfluid neutron matter. We determine that the matter density profile of a vortex shows a sig…
Spin 1/2 Fermions in the Unitary Regime: A Superfluid of a New Type
Aurel Bulgac, Joaquin E. Drut, Piotr Magierski
We have studied, in a fully non-perturbative calculation, a dilute system of spin 1/2 interacting fermions, characterized by an infinite scattering length at finite temperatures. V…
Dilute Quantum Droplets
Aurel Bulgac
In the limit when the two-body scattering length is negative and much larger than the effective two-body interaction radius the contribution to the ground state energy due to t…
Neck Rupture and Scission Neutrons in Nuclear Fission
Ibrahim Abdurrahman, Matthew Kafker, Aurel Bulgac +1
Just before a nucleus fissions a neck is formed between the emerging fission fragments. It is widely accepted that this neck undergoes a rather violent rupture, despite no direct e…
Fragment Intrinsic Spins and Fragments' Relative Orbital Angular Momentum in Nuclear Fission
Aurel Bulgac, Ibrahim Abdurrahman, Kyle Godbey +1
We present the first fully unrestricted microscopic calculations of the primary fission fragment intrinsic spins and of the fission fragments' relative orbital angular momentum for…
Influence of the Exit Channel in U(n,f) and Pu(n,f) Reactions in Time-Dependent Density Functional Theory
Ibrahim Abdurrahman, Matthew Kafker, Aurel Bulgac +1
This study investigates the consequences of the intrinsic deformation of the fissioning nuclear system near the outer saddle point on the shape evolution of the nucleus from saddle…
The angular correlation between the fission fragment intrinsic spins
Aurel Bulgac
The generation of fission fragments (FF) spins and of their relative orbital angular momentum has been debated for more than six decades and no consensus has been yet achieved so f…
Time-Dependent Density Functional Theory for Fermionic Superfluids: from Cold Atomic Gases, to Nuclei and Neutron Stars Crust
Aurel Bulgac
In cold atoms and in the crust of neutron stars the pairing gap can reach values comparable with the Fermi energy. While in nuclei the neutron gap is smaller, it is still of the or…
Shell correction energy for bubble nuclei
Yongle Yu, Aurel Bulgac, Piotr Magierski
The positioning of a bubble inside a many fermion system does not affect the volume, surface or curvature terms in the liquid drop expansion of the total energy. Besides possible C…
Zero Temperature Thermodynamics of Asymmetric Fermi Gases at Unitarity
Aurel Bulgac, Michael McNeil Forbes
The equation of state of a dilute two-component asymmetric Fermi gas at unitarity is subject to strong constraints, which affect the spatial density profiles in atomic traps. These…
The Unitary Fermi Gas: From Monte Carlo to Density Functionals
Aurel Bulgac, Michael McNeil Forbes, Piotr Magierski
In this chapter, we describe three related studies of the universal physics of two-component unitary Fermi gases with resonant short-ranged interactions. First we discuss an ab ini…
Scalar Casimir effect between Dirichlet spheres or a plate and a sphere
Aurel Bulgac, Piotr Magierski, Andreas Wirzba
We present a simple formalism for the evaluation of the Casimir energy for two spheres and a sphere and a plane, in case of a scalar fluctuating field, valid at any separations. We…
Hartree--Fock--Bogoliubov Approximation for Finite Systems
Aurel Bulgac
Some general features of the spectrum of the Hartree-Fock-Bogoliubov equations are examined. Special attention is paid to the asymptotic behavior of the single quasiparticle wave f…
Casimir Interaction among Objects Immersed in a Fermionic Environment
Aurel Bulgac, Andreas Wirzba
Using ensembles of two, three and four spheres immersed in a fermionic background we evaluate the (integrated) density of states and the Casimir energy. We thus infer that for suff…
Induced P-wave superfluidity within full energy-momentum dependent Eliashberg approximation in asymmetric dilute Fermi gases
Aurel Bulgac, Sukjin Yoon
We consider a very asymmetric system of Fermions with an interaction characterized by a positive scattering length only. The minority atoms pair and form a BEC of dimers, while the…
Vortex Rings in a Trap
Aurel Bulgac, Michael McNeil Forbes
We present a simple Hamiltonian description of the dynamics of a quantized vortex ring in a trapped superfluid, compare this description with dynamical simulations, and characteriz…
Towards Quantum Turbulence in Cold Atomic Fermionic Superfluids
Aurel Bulgac, Michael McNeil Forbes, Gabriel WlazÅowski
Fermionic superfluids provide a new realization of quantum turbulence, accessible to both experiment and theory, yet relevant to phenomena from both cold atoms to nuclear astrophys…
Local Density Approximation for Systems with Pairing Correlations
Aurel Bulgac
I formulate a local density approximation for fermion systems with pairing correlations based on a rapidly converging renormalization scheme for the pairing gap.
Properties of nuclei in the neutron star crust
Piotr Magierski, Aurel Bulgac, Paul-Henri Heenen
In the present study we investigate the static properties of nuclei in the inner crust of neutron stars. Using the Hartree-Fock method in coordinate space, together with the semicl…
Thermodynamics of a Trapped Unitary Fermi Gas
Aurel Bulgac, Joaquin E. Drut, Piotr Magierski
We present the first model-independent comparison of recent measurements of the entropy and of the critical temperature of a unitary Fermi gas, performed by Luo et al., with the mo…
Molecular transitions in Fermi condensates
Aurel Bulgac, George F. Bertsch
We discuss the transition of fermion systems to a condensate of Bose dimers, when the interaction is varied by use of a Feshbach resonance. We argue that there is an intermediate p…
A dilute atomic Fermi system with a large positive scattering length
Aurel Bulgac, Paulo F. Bedaque, Antonio C. Fonseca
We show that a dilute atomic Fermi system at sufficiently low temperatures, can display fermionic superfluidity, even in the case of a repulsive atom-atom interaction, when the sca…
Local Density Functional Theory for Superfluid Fermionic Systems: The Unitary Gas
Aurel Bulgac
The first detailed comparison between ab initio calculations of finite fermionic superfluid systems, performed recently by Chang and Bertsch [Phys. Rev. A 76, 021603(R), (2007)] an…
Neutron Stars and Quantum Billiards
Aurel Bulgac, Piotr Magierski
Homogeneous neutron matter at subnuclear densities becomes unstable towards the formation of inhomogeneities. Depending on the average value of the neutron density one can observe…
Spin 1/2 Fermions in the Unitary Regime at Finite Temperature
Aurel Bulgac, Joaquin E. Drut, Piotr Magierski
We have performed a fully non-perturbative calculation of the thermal properties of a system of spin 1/2 fermions in 3D in the unitary regime. We have determined the critical tempe…
Superfluid LDA (SLDA): Local Density Approximation for Systems with Superfluid Correlations
Aurel Bulgac, Yongle Yu
We present a concise account of our development of the first genuine Local Density Approximation (LDA) to the Energy Density Functional (EDF) for fermionic systems with superfluid…
Dynamics of Complex Quantum Systems: Dissipation and Kinetic Equations
Aurel Bulgac, Giu Do Dand, Dimitri Kusnezov
We present a microscopic approach to quantum dissipation and sketch the derivation of the kinetic equation describing the evolution of a simple quantum system in interaction with a…
Restoring Broken Symmetries for Nuclei and Reaction Fragments
Aurel Bulgac
In typical microscopic approaches, particularly when pairing correlations are present, nuclei and nuclear fragments do not have well defined quantum numbers and symmetries should b…
Emergence of a pseudogap in the BCS-BEC crossover
Adam Richie-Halford, JoaquÃn E. Drut, Aurel Bulgac
Strongly correlated Fermi systems with pairing interactions become superfluid below a critical temperature . The extent to which such pairing correlations alter the behavior o…
Exotic nuclear phases in the inner crust of neutron stars in the light of Skyrme-Hartree-Fock theory
Piotr Magierski, Aurel Bulgac, Paul-Henri Heenen
The bottom part of the neutron star crust is investigated using the Skyrme-Hartree-Fock approach with the Coulomb interaction treated beyond the Wigner-Seitz approximation. A varie…
Examining the justification for the introduction of a fermion localization function
Aurel Bulgac
Becke and Edgecombe suggested in 1990 a theoretical tool to describe electron localization in atoms and molecules, an idea which was borrowed by a large number of nuclear theorists…
Perfect-fluid behavior of a dilute Fermi gas near unitary
Gabriel WlazÅowski, Wei Quan, Aurel Bulgac
We present an ab initio calculation of the shear viscosity as a function of interaction strength in a two-component unpolarized Fermi gas near the unitary limit, within a finite te…