scholarly journals Logical strength of complexity theory and a formalization of the PCP theorem in bounded arithmetic

2015 ◽  
Vol 11 (2) ◽  
Author(s):  
Ján Pich
Keyword(s):  
Complexity Theory ◽  
Bounded Arithmetic ◽  
Pcp Theorem ◽  
Logical Strength

scholarly journals Finitisation in Bounded Arithmetic

1994 ◽  
Vol 1 (23) ◽  
Author(s):  
Søren Riis
Keyword(s):  
Complexity Theory ◽  
Bounded Arithmetic ◽  
Open Problems ◽  
Precise Sense ◽  
Fourth Level ◽  
Deep Problem ◽  
New Type ◽  
And Function ◽  
Separation Problems

I prove various results concerning un-decidability in weak fragments of Arithmetic. All results are concerned with S^{1}_{2} \subseteq T^{1}_{2} \subseteq S^{2}_{2} \subseteq T^{2}_{2} \subseteq.... a hierarchy of theories which have already been intensively studied in the literature. Ideally one would like to separate these systems. However this is generally expected to be a very deep problem, closely related to some of the most famous and open problems in complexity theory.<br /> <br />In order to throw some light on the separation problems, I consider the case where the underlying language is enriched by extra relation and function symbols. The paper introduces a new type of results. These state that the first three levels in the hierarchy (i.e. S^{1}_{2}, T^{1}_{2} and S^{2}_{2}) are never able to distinguish (in a precise sense) the "finite'' from the "infinite''. The fourth level (i.e. T^{2}_{2}) in some cases can make such a distinction. More precisely, elementary principles from finitistical combinatorics (when expressed solely by the extra relation and function symbols) are only provable on the first three levels if they are valid when considered as principles of general (infinitistical) combinatorics. I show that this does not hold for the fourth level.<br /> <br />All results are proved by forcing.

Complexity theory and psychoanalysis

2005 ◽  
Author(s):  
Katherine Harper
Keyword(s):  
Complexity Theory

When reality bites back: Chaos/complexity theory for advocate leaders

2009 ◽  
Author(s):  
Michele B. Hill ◽  
Gregory L. Brack ◽  
Lydia Odenat
Keyword(s):  
Complexity Theory

Articulating a strategic approach to face complexity in design projects

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Luca SIMEONE ◽  
David DRABBLE ◽  
Giorgia IACOPINI ◽  
Kirsten VAN DAM ◽  
Nicola MORELLI ◽  
...  
Keyword(s):  
Complexity Theory ◽  
Wicked Problems ◽  
Theory Of Change ◽  
Strategic Action ◽  
Community Initiatives ◽  
Uncertain Environment ◽  
Strategic Approach ◽  
Design Projects

In today’s world of global wicked problems, constraints and imperatives imposed by an external and uncertain environment render strategic action a quite complex endeavour. Since the 1990s, within community initiatives and philanthropic projects, the construct of Theory of Change has been used to address such complexity. Theory of Change can be defined as the systematic and cumulative study of the links between the activities, outcomes, and context of an intervention. The area of focus for this paper is to explore whether Theory of Change can support more strategic approaches in design. In particular, the paper examines how Theory of Change was applied to DESIGNSCAPES - a project oriented, among other things, toward offering a supporting service for all those city actors interested in using design to develop urban innovation initiatives that tackle complex issues of broad concern.

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