Scientists / Open questions

John J. Hopfield

Neural networks; condensed matter physics; biophysics

2024 Nobel Prize in Physics

13 questions

Collective dynamics of pulse-coupled threshold-element systems beyond the convergence regime: avalanche exponents, supercritical and inhibitory coupling, attractor measures, and energy-function programming (Herz–Hopfield 1995)
Diagnostic attribution of the cohesive-energy and phonon discrepancies of the Topp-Hopfield cosine pseudopotential for sodium
Neurodynamics of mental exploration: the unresolved biological grounding, closed-loop control, and experimental validation of Hopfield's adaptation-based model
Extending unsupervised learning by competing hidden units beyond one fully connected layer: depth iteration, scale, biological realism, and theory of the fast heuristic
Unresolved adversarial-robustness questions for dense associative memory classifiers: role of the full training rule, adversarial training, convolutional extension, and interaction-power regime
Quantitative completion of the effective-impurity model of optical absorption edges in amorphous semiconductors: donor and donor-acceptor pair transitions, realistic charge distributions, controlled approximations, and stable inversion of measured $\varepsilon_{2}(\omega)$ to the band-tail density of states
Unified co-development of feedforward and intracortical feedback connections in the adapting-synapse model of visual cortical development (Dong and Hopfield, 1992)
Economic feasibility of mapping optimization problems onto second-order neural-network computation: conditions and fair comparison with conventional computing
Computation beyond energy descent: a theory for asymmetric, oscillatory, and chaotic recurrent neural dynamics, and principled escape from poor attractors in analog optimization networks
All-or-none versus graded expression of long-term potentiation at individual hippocampal CA3-CA1 synapses
Analytical theory of the Ponulak–Hopfield wavefront path-planning network: capacity, phase boundaries, and parameter tradeoffs under anti-STDP wave writing and synaptic reset
Learning, theoretical completion, and validation of the collective-activity-coordinate recognizer for time-varying patterns (Hopfield, 2015)
Thermodynamic and structural mechanism of the inositol hexaphosphate–induced shift of the heme-iron spin-state equilibrium in methemoglobins

Back to open problems

Collective dynamics of pulse-coupled threshold-element systems beyond the convergence regime: avalanche exponents, supercritical and inhibitory coupling, attractor measures, and energy-function programming (Herz–Hopfield 1995)

Diagnostic attribution of the cohesive-energy and phonon discrepancies of the Topp-Hopfield cosine pseudopotential for sodium

Neurodynamics of mental exploration: the unresolved biological grounding, closed-loop control, and experimental validation of Hopfield's adaptation-based model

Extending unsupervised learning by competing hidden units beyond one fully connected layer: depth iteration, scale, biological realism, and theory of the fast heuristic

Unresolved adversarial-robustness questions for dense associative memory classifiers: role of the full training rule, adversarial training, convolutional extension, and interaction-power regime

Unified co-development of feedforward and intracortical feedback connections in the adapting-synapse model of visual cortical development (Dong and Hopfield, 1992)

Economic feasibility of mapping optimization problems onto second-order neural-network computation: conditions and fair comparison with conventional computing

Computation beyond energy descent: a theory for asymmetric, oscillatory, and chaotic recurrent neural dynamics, and principled escape from poor attractors in analog optimization networks

All-or-none versus graded expression of long-term potentiation at individual hippocampal CA3-CA1 synapses

Analytical theory of the Ponulak–Hopfield wavefront path-planning network: capacity, phase boundaries, and parameter tradeoffs under anti-STDP wave writing and synaptic reset

Learning, theoretical completion, and validation of the collective-activity-coordinate recognizer for time-varying patterns (Hopfield, 2015)

Thermodynamic and structural mechanism of the inositol hexaphosphate–induced shift of the heme-iron spin-state equilibrium in methemoglobins