Correlation Dynamics of Yukawa-theory in 1+1 dimensions

Using the method of correlation dynamics we investigate the properties of a field-theory for fermions and scalar bosons coupled via a Yukawa interaction. Within this approach, which consists in an expansion of full equal-time Green functions into connected equal-time Green functions and a corresponding truncation of the hierarchy of equations of motion we carry out calculations up to 4th order in the connected Green functions and evaluate the effective potential of the theory in 1+1 dimensions on a torus. Comparing the different approximations we find a strong influence of the connected 4-point functions on the properties of the system.Comment: LaTeX, 38 pages, 12 figure

Constraint Correlation Dynamics of SU(N) Gauge Theories

A constraint correlation dynamics up to 4-point Green functions is proposed for SU(N) gauge theories which reduces the N-body quantum field problem to the two-body level. The resulting set of nonlinear coupled equations fulfills all conservation laws including fermion number, linear and angular momenta as well as the total energy. Apart from the conservation laws in the space-time degrees of freedom the Gauss law is conserved as a quantum expectation value identically for all times. The same holds for the Ward identities as generated by commutators of Gauss operators. The constraint dynamical equations are highly non-perturbative and thus applicable also in the strong coupling regime, as e.g. low-energy QCD problems.Comment: 26 pages, LATEX, UGI-94-0

New Source Term for QGP Formation in the Background-Field Model

We consider pair production in a space-time-dependent background field and derive a source term, i.e., production rate in the one-particle phase space. Such a source term is required in Boltzmann-equation-based models of quark-gluon plasma formation and evolution. We compare the source term derived here with the one that has been used in the literature so far. Significant differences are observed.Comment: 12 pages latex and 4 post-script figure

How odd: Diverging effects of predictability and plausibility violations on sentence reading and word memory

How do violations of predictability and plausibility affect online language processing? How does it affect longer-term memory and learning when predictions are disconfirmed by plausible or implausible words? We investigated these questions using a self-paced sentence reading and noun recognition task. Critical sentences violated predictability or plausibility or both, for example, “Since Anne is afraid of spiders, she doesn’t like going down into the … basement (predictable, plausible), garden (unpredictable, somewhat plausible), moon (unpredictable, deeply implausible).” Results from sentence reading showed earlier-emerging effects of predictability violations on the critical noun, but later-emerging effects of plausibility violations after the noun. Recognition memory was exclusively enhanced for deeply implausible nouns. The earlier-emerging predictability effect indicates that having word form predictions disconfirmed is registered very early in the processing stream, irrespective of semantics. The later-emerging plausibility effect supports models that argue for a staged architecture of reading comprehension, where plausibility only affects a post-lexical integration stage. Our memory results suggest that, in order to facilitate memory and learning, a certain magnitude of prediction error is required

Effects of prediction error on episodic memory retrieval: evidence from sentence reading and word recognition

Prediction facilitates word processing in the moment, but the longer-term consequences of prediction remain unclear. We investigated whether prediction error during language encoding enhances memory for words later on. German-speaking participants read sentences in which the gender marking of the pre-nominal article was consistent or inconsistent with the predictable noun. During subsequent word recognition, we probed participants’ recognition memory for predictable and unpredictable nouns. Our results indicate that individuals who demonstrated early prediction error during sentence reading, showed enhanced recognition memory for nouns overall. Results from an exploratory step-wise regression showed that prenominal prediction error and general reading speed were the best proxies for recognition memory. Hence, prediction error may facilitate recognition by furnishing memory traces built during initial reading of the sentences. Results are discussed in the light of hypotheses positing that predictable words show a memory disadvantage because they are processed less thoroughly

Hedging Bets in Linguistic Prediction : Younger and Older Adults Vary in the Breadth of Predictive Processing

Language processing is predictive in nature, but it is unknown whether language users generate multiple predictions about upcoming content simultaneously or whether spreading activation from one pre-activated word facilitates other words downstream. Simultaneously, developmental accounts of predictive processing simultaneously highlight potential tension among spreading activation vs. multiple activation accounts. We used self-paced reading to investigate if younger and older readers of German generate (multiple) graded predictions about the grammatical gender of nouns. Gradedness in predictions was operationalized as the difference in cloze probability between the most likely and second-most likely continuation that could complete a sentence. Sentences with a greater probabilistic difference were considered as imbalanced and more biased towards one gender. Sentences with lower probabilistic differences were considered to be more balanced towards multiple genders. Both young and older adults engaged in predictive processing. However, only younger adults activated multiple predictions, with slower reading times (RTs) when gender representations were balanced, but facilitation when one gender was more likely than others. In contrast, older adults’ RTs did not pattern with imbalance but merely with predictability, showing that, while able to generate predictions based on context, older adults did not predict multiple gender continuations. Hence, our findings suggest that (younger) language users generate graded predictions about upcoming content, by weighing possible sentence continuations according to their difference in cloze probability. Compared to younger adults, older adults’ predictions are reduced in scope. The results provide novel theoretical insights into the developmental mechanisms involved in predictive processing

Regularity estimates for elliptic equations involving fractional Neumann boundary conditions

We prove regularity estimates for elliptic equations involving fractional Neumann boundary conditions. In particular, we consider solutions which are harmonic in a Lipschitz domain with a fractional normal derivative boundary condition. To establish various estimates, we utilize the extension problem characterization for the normal derivative, and develop a De Giorgi type theory for our case. In total, we prove interior and boundary Schauder estimates for the aforementioned solutions

A congregational church for Melrose Highlands, Massachusetts

Thesis (B.Arch.) Massachusetts Institute of Technology. Dept. of Architecture, 1951.MIT copy bound with: Women's hostel for Bethune College, Calcutta / B. N. Banerjea. 1951. Accompanying drawings held by MIT Museum.Vita.Bibliography: leaves 88-90.by Charles Haeuser.B.Arch