John Z. Imbrie
University of Virginia
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Featured researches published by John Z. Imbrie.
Journal of Statistical Physics | 1988
John Z. Imbrie; Thomas Spencer
We consider a system of random walks or directed polymers interacting weakly with an environment which is random in space and time. In spatial dimensionsd>2, we establish that the behavior is diffusive with probability one. The diffusion constant is not renormalized by the interaction.
Journal of Statistical Physics | 2016
John Z. Imbrie
For a one-dimensional spin chain with random local interactions, we prove that many-body localization follows from a physically reasonable assumption that limits the amount of level attraction in the system. The construction uses a sequence of local unitary transformations to diagonalize the Hamiltonian and connect the exact many-body eigenfunctions to the original basis vectors.
Annals of Surgery | 2001
Marcia M. Moore; Lawrence A. Whitney; T. Lisa Cerilli; John Z. Imbrie; Michael Bunch; Virginia B. Simpson; John B. Hanks
ObjectiveTo evaluate the efficacy of intraoperative ultrasound in obtaining adequate surgical margins in women undergoing lumpectomy for palpable breast cancer. Summary Background DataAdequacy of surgical margins is a subject of debate in the literature for women undergoing breast-conserving therapy. The emerging technology of intraoperative ultrasound-guided surgery lends itself well to a prospective study evaluating surgical accuracy and margin status after lumpectomy. MethodsTwo groups of women undergoing lumpectomy for palpable breast cancer were studied, one group using intraoperative ultrasound (n = 27) and the other without (n = 24). Pathologic specimens were evaluated for size, margins, and accuracy, and patients were questioned about satisfaction with cosmetic results. ResultsSurgical accuracy was improved with intraoperative ultrasound-guided surgery. Margin status was improved, patient satisfaction was equivalent, and cost was not affected using ultrasound technology. Intraoperative ultrasound appears especially efficacious for women whose preoperative mammogram shows dense parenchyma surrounding the lesion. ConclusionsThe use of ultrasound-guided surgery optimizes the surgeon’s ability to obtain satisfactory margins for breast-conserving techniques in patients with breast cancer. Patient satisfaction is excellent and a cost savings is most likely realized.
Annals of Surgery | 2000
Marcia M. Moore; Girum Borossa; John Z. Imbrie; Robert E. Fechner; Jennifer A. Harvey; Craig L. Slingluff; Reid B. Adams; John B. Hanks
OBJECTIVE To determine whether infiltrating lobular carcinoma (ILC) is associated with high positive-margin rates for single-stage lumpectomy procedures, and to define clinical, mammographic, or histologic characteristics of ILC that might influence the positive-margin rate, thereby affecting treatment decisions. SUMMARY BACKGROUND DATA Infiltrating lobular cancer represents approximately 10% of all invasive breast carcinomas and is often poorly defined on gross examination. METHODS A group of 47 patients with biopsy-proven ILC undergoing breast-conservation therapy (BCT) at the University of Virginia Health Sciences Center between 1975 and 1999 was compared with a group of 150 patients with infiltrating ductal cancer undergoing BCT during the same time period. The pathology of the lumpectomy specimen was reviewed for each patient to confirm surgical margin status. Office and surgical notes as well as mammography reports were examined to determine whether the lesions were deemed palpable before and during surgery. Patients were stratified according to age, family history, tumor size, tumor location, and histologic features of the tumor. RESULTS The incidence of positive margins was greater in the ILC group compared with the infiltrating ductal cancer group. Patient age, family history, and preoperative palpability of the tumor did not correlate with surgical margin status. Of the mammographic features identified, including spiculated mass, calcifications, architectural distortion, and other densities, only architectural distortion predicted positive surgical margin status. Tumor grade, tumor size, lymph node status, and receptor status were not predictive of surgical margin status. CONCLUSIONS For patients with ILC, BCT is feasible, but these patients are at high risk of tumor-positive resection margins (51% incidence) after the initial resection. Only the mammographic finding of architectural distortion was identified as a preoperative marker reliably identifying a subgroup of ILC patients at especially high risk for a positive surgical margin. For all patients with ILC considering BCT, careful counseling about the potential need for a second procedure to treat the positive margin should be included in the treatment discussion.
Communications in Mathematical Physics | 1989
Christian Borgs; John Z. Imbrie
We construct the phase diagram of any system which admits a low-temperature polymer or cluster expansion. Such an expansion turns the system into a hard-core interacting contour model with small, but not necessarily positive, activities. The method uses some of Zahradniks ideas [Z1], but applies equally well to systems with complex interactions. We give two applications. First, to low-temperatureP(φ)2 models with complex couplings; and second, to a computation of asymptotics of partition functions in periodic volumes. If the index of a supersymmetric field theory is known, the second application would help determine the number of phases in infinite volume.
Communications in Mathematical Physics | 1988
John Z. Imbrie; Charles M. Newman
We rigorously establish the existence of an intermediate ordered phase in one-dimensional 1/|x−y|2 percolation, Ising and Potts models. The Ising model truncated two-point function has a power law decay exponent θ which ranges from its low (and high) temperature value of two down to zero as the inverse temperature and nearest neighbor coupling vary. Similar results are obtained for percolation and Potts models.
Physical Review Letters | 2016
John Z. Imbrie
We consider a weakly interacting quantum spin chain with random local interactions. We prove that many-body localization follows from a physically reasonable assumption that limits the extent of level attraction in the statistics of eigenvalues. In a Kolmogorov-Arnold-Moser-style construction, a sequence of local unitary transformations is used to diagonalize the Hamiltonian by deforming the initial tensor-product basis into a complete set of exact many-body eigenfunctions.
Communications in Mathematical Physics | 1985
John Z. Imbrie
We prove that the three-dimensional Ising model in a random magnetic field exhibits long-range order at zero temperature and small disorder. Hence the lower critical dimension for this model is two (or less) and not three as has been suggested by some.
Communications in Mathematical Physics | 1981
John Z. Imbrie
AbstractLow temperature phase diagrams of two-dimensional quantum field models are constructed. Let lie in an (r−1)-dimensional space of perturbations of a polynomial withr degenerate minima. Perform a scaling and assume λ«1. We constructk distinct states on
Communications in Mathematical Physics | 1984
Jürg Fröhlich; John Z. Imbrie