Is transport in time-dependent random potentials universal ?

The growth of the average kinetic energy of classical particles is studied for potentials that are random both in space and time. Such potentials are relevant for recent experiments in optics and in atom optics. It is found that for small velocities uniform acceleration takes place, and at a later stage fluctuations of the potential are encountered, resulting in a regime of anomalous diffusion. This regime was studied in the framework of the Fokker-Planck approximation. The diffusion coefficient in velocity was expressed in terms of the average power spectral density, which is the Fourier transform of the potential correlation function. This enabled to establish a scaling form for the Fokker-Planck equation and to compute the large and small velocity limits of the diffusion coefficient. A classification of the random potentials into universality classes, characterized by the form of the diffusion coefficient in the limit of large and small velocity, was performed. It was shown that one dimensional systems exhibit a large variety of novel universality classes, contrary to systems in higher dimensions, where only one universality class is possible. The relation to Chirikov resonances, that are central in the theory of Chaos, was demonstrated. The general theory was applied and numerically tested for specific physically relevant examples.Comment: 5 pages, 3 figure

Characterization of low-energy magnetic excitations in chromium

The low-energy excitations of Cr, i.e. the Fincher-Burke (FB) modes, have been investigated in the transversely polarized spin-density-wave phase by inelastic neutron scattering using a single-(Q+-) crystal with a propagation vector (Q+-) parallel to [0,0,1]. The constant-momentum-transfer scans show that the energy spectra consist of two components, namely dispersive FB modes and an almost energy-independent cross section. Most remarkably, we find that the spectrum of the FB modes exhibits one peak at 140 K near Q = (0,0,0.98) and two peaks near Q = (0,0,1.02), respectively. This is surprising because Cr crystallizes in a centro-symmetric bcc structure. The asymmetry of those energy spectra decreases with increasing temperature. In addition, the observed magnetic peak intensity is independent of Q suggesting a transfer of spectral-weight between the upper and lower FB modes. The energy-independent cross section is localized only between the incommensurate peaks and develops rapidly with increasing temperature.Comment: 6 pages, 8 figure

Locating the International Interest in Intranational Cultural Property Disputes

This Article considers the extent to which there may be an international interest in how intranational disputes over cultural property are settled. Drawing on the norms underlying recent global scrutiny of states’ destruction of cultural objects located within their own territory, I identify two factors that may justify internationalizing otherwise domestic conflicts over cultural property: discriminatory intent and harm to cultural diversity. I argue that where neither of these concerns is implicated, the international community should pursue a policy of non-intervention, both because local authorities are likely to be more competent adjudicators and because eliciting a global referendum on cultural identity risks sapping that identity of its fluidity. At the same time, maintaining neutrality is inappropriate when one claimant’s asserted right would actually undermine this legal regime’s multiculturalist goals. The claim of group ownership over a cultural object acquired through persecution of minority communities abuses a property right whose ostensible rationale is promotion of cultural diversity. This frustration of purpose ought to give the international community a significantly higher interest in ensuring that a claim does not untether the property right from the theory that justifies it. The Article concludes by calling for recognition of cultural property rights as a purposive legal scheme that is susceptible to exploitation, in domestic and international arenas alike

The Copy Process

There’s more than one way to copy. The process of copying can be laborious or easy, expensive or cheap, educative or unenriching. But the two intellectual property regimes that make copying an element of liability, copyright and trade secrecy, approach these distinctions differently. Copyright conflates them. Infringement doctrine considers all copying processes equally suspect, asking only whether the resulting product is substantially similar to the protected work. By contrast, trade secrecy asks not only whether but also how the defendant copied. It limits liability to those who appropriate information through means that the law deems improper. This Article argues that copyright doctrine should borrow a page from trade secrecy by factoring the defendant’s copying process into the infringement analysis. To a wide range of actors within the copyright ecosystem, differences in process matter. Innovators face less risk from competitors if imitation is costly than if it is cheap. Consumers may value a work remade from scratch more than they do a digital reproduction. Beginners can learn more technical skills from deliberately tracing an expert’s creative steps than from simply clicking cut and paste. The consequences of copying, in short, often depend on how the copies are made. Fortunately, getting courts to consider process in copyright cases may not be as far-fetched as the doctrine suggests. Black-letter law notwithstanding, courts sometimes subtly invoke the defendant’s process when ostensibly assessing the propriety of the defendant’s product. While these decisions are on the right track, it’s time to bring process out into the open. Copyright doctrine could be both more descriptively transparent and more normatively attractive by expressly looking beyond the face of a copy and asking how it got there

Music as a Matter of Law

What is a musical work? Philosophers debate it, but for judges the answer has long been simple: music means melody. Though few recognize it today, that answer goes all the way back to the birth of music copyright litigation in the nineteenth century. Courts adopted the era’s dominant aesthetic view identifying melody as the site of originality and, consequently, the litmus test for similarity. Surprisingly, music’s single-element test has persisted as an anomaly within the modern copyright system, where typically multiple features of eligible subject matter are eligible for protection. Yet things are now changing. Recent judicial decisions are beginning to break down the old definitional wall around melody, looking elsewhere within the work to find protected expression. Many have called this increasing scope problematic. This Article agrees—but not for the reason that most people think. The problem is not, as is commonly alleged, that these decisions are unfaithful to bedrock copyright doctrine. A closer inspection reveals that, if anything, they are in fact more faithful than their predecessors. The problem, rather, is that the bedrock doctrine itself is misguided. Copyright law, unlike patent law, has never shown any interest in trying to increase the predictability of its infringement test, leaving second comers to speculate as to what might or might not be allowed. But the history of music copyright offers a valuable look at a path not taken, an accidental experiment where predictability was unwittingly achieved by consistently emphasizing a single element out of a multi-element work. As a factual matter, the notion that melody is the primary locus of music’s value is a fiction. As a policy matter, however, that fiction has turned out to be useful. While its original, culturally-myopic rationale should be discarded, music’s unidimensional test still offers underappreciated advantages over the “everything counts” analysis that the rest of the copyright system long ago chose

Honest Copying Practices

One of intellectual property theory’s operating assumptions is that creating is hard while copying is easy. But it is not always so. Copies, though outwardly identical, can come from different processes, from cheap digital duplication to laborious handmade re-creation. Policymakers around the world face a choice whether such distinctions should affect liability. The two branches of intellectual property that condition liability on actual copying, copyright and trade secrecy, give different answers. Both in the United States and elsewhere, trade secrecy regimes distinguish between copying methods deemed illegitimate and those deemed legitimate, what international treaties call “honest commercial practices.” Copyright regimes, by contrast, are largely indifferent. They focus on the end product, not the process of its production. Trade secrecy and copyright are not often seen as a natural pair, but on the question of how copies are made, the former has much to offer the latter. This Article examines how a defendant’s method of copying could function as a policy lever within international copyright law. Because differences in method can matter to copyright policy’s intended beneficiaries—owners, readers, and follow-on authors—it should also matter to copyright policy’s crafters. Yet before that goal can be implemented, there seems to be a stumbling block. International treaty commitments require member states to provide owners an exclusive reproduction right that covers copying performed in any manner. Nevertheless, that commitment has not stopped states from treating laborious copying differently than cheap copying in limited contexts, such as private uses. The problem is that the normative rationale underlying these limited exceptions remains understudied and therefore unsystematically implemented. A closer inspection reveals that the same flexibilities in international law that have allowed states to make these exceptions also allow them to consider the defendant’s method of copying as a structural element of the reproduction right itself. The resulting regime would look something like trade secrecy’s tolerance for honest commercial practices—what I dub here “honest copying practices.

Honest Copying Practices

One of intellectual property theory’s operating assumptions is that creating is hard while copying is easy. But it is not always so. Copies, though outwardly identical, can come from different processes, from cheap digital duplication to laborious handmade re-creation. Policymakers around the world face a choice whether such distinctions should affect liability. The two branches of intellectual property that condition liability on actual copying, copyright and trade secrecy, give different answers. Both in the United States and elsewhere, trade secrecy regimes distinguish between copying methods deemed illegitimate and those deemed legitimate, what international treaties call “honest commercial practices.” Copyright regimes, by contrast, are largely indifferent. They focus on the end product, not the process of its production. Trade secrecy and copyright are not often seen as a natural pair, but on the question of how copies are made, the former has much to offer the latter. This Article examines how a defendant’s method of copying could function as a policy lever within international copyright law. Because differences in method can matter to copyright policy’s intended beneficiaries — owners, readers, and follow-on authors — it should also matter to copyright policy’s crafters. Yet before that goal can be implemented, there seems to be a stumbling block. International treaty commitments require member states to provide owners an exclusive reproduction right that covers copying performed in any manner. Nevertheless, that commitment has not stopped states from treating laborious copying differently than cheap copying in limited contexts, such as private uses. The problem is that the normative rationale underlying these limited exceptions remains understudied and therefore unsystematically implemented. A closer inspection reveals that the same flexibilities in international law that have allowed states to make these exceptions also allow them to consider the defendant’s method of copying as a structural element of the reproduction right itself. The resulting regime would look something like trade secrecy’s tolerance for honest commercial practices — what I dub here “honest copying practices.

Creating Around Copyright

It is generally understood that the copyright system constrains downstream creators by limiting their ability to use protected works in follow-on expression. Those who view the promotion of creativity as copyright’s mission usually consider this constraint to be a necessary evil at best and an unnecessary one at worst. This conventional wisdom rests on the seemingly intuitive premise that more creative choice will deliver more creativity. Yet that premise is belied by both the history of the arts and contemporary psychological research on the creative process. In fact, creativity flourishes best not under complete freedom, but rather under a moderate amount of restriction. Drawing from work in cognitive psychology, management studies, and art history, this Article argues that contemporary copyright discourse has overlooked constraint’s generative upside. The Article unpacks the concept of constraint into seven characteristics: source, target, scope, clarity, timing, severity, and polarity. These characteristics function as levers that determine a given constraint’s generative potential. Variation in that potential provides an underappreciated theoretical justification for areas in which copyright law is restrictive, such as the exclusive derivative work right, as well as areas where it is permissive, such as the independent creation and fair use defenses. The Article reveals that the incentives versus access debate that has long dominated copyright theory has misunderstood the relationship between creativity and constraint. Information may want to be free, but creativity does not

Locating the International Interest in Intranational Cultural Property Disputes

This Article considers the extent to which there may be an international interest in how intranational disputes over cultural property are settled. Drawing on the norms underlying recent global scrutiny of states’ destruction of cultural objects located within their own territory, I identify two factors that may justify internationalizing otherwise domestic conflicts over cultural property: discriminatory intent and harm to cultural diversity. I argue that where neither of these concerns is implicated, the international community should pursue a policy of non-intervention, both because local authorities are likely to be more competent adjudicators and because eliciting a global referendum on cultural identity risks sapping that identity of its fluidity. At the same time, maintaining neutrality is inappropriate when one claimant’s asserted right would actually undermine this legal regime’s multiculturalist goals. The claim of group ownership over a cultural object acquired through persecution of minority communities abuses a property right whose ostensible rationale is promotion of cultural diversity. This frustration of purpose ought to give the international community a significantly higher interest in ensuring that a claim does not untether the property right from the theory that justifies it. The Article concludes by calling for recognition of cultural property rights as a purposive legal scheme that is susceptible to exploitation, in domestic and international arenas alike

Similar Secrets

A foundational question in every dispute over intellectual property is whether the defendant’s product is too similar to the plaintiff ’s. For almost all intellectual property regimes, an extensive body of case law and academic commentary has examined how such similarity should be measured. Trade secrecy, however, remains a remarkable exception. In trade secrecy cases, just as in other intellectual property cases, the defendant’s good or method can diverge markedly from what the plaintiff developed. Yet it turns out that trade secret case law provides little guidance for assessing how much similarity is too much. The standard remains, fittingly but frustratingly, a secret. This Article takes the first close look at what that standard should be. We argue that trade secrecy’s similarity framework is currently asking an incomplete set of questions. It inquires almost exclusively into the defendant’s innovation steps, instructing factfinders to determine whether the defendant had acquired any advantage from familiarity with the secret. In doing so, it wrongly skips over an inquiry into the end product or process that the defendant is actually exploiting. A better test would consider not only the defendant’s benefit from knowing the secret, but also the kind of exploitable asset that the benefit ultimately translates into. Under our proposal, claims for misappropriation through either improper acquisition or disclosure would remain largely the same. But misappropriation through use would change. A defendant wouldn’t be liable for using a lawfully acquired secret unless it is exploiting an asset that incorporates material elements from the owner’s secret in a manner that the plaintiff actually foresaw or, given industry trends, could reasonably have foreseen